James Kanagasooriam

Chief Research Officer

Bi_Focal #13: Biden's Achilles Heel?

February 23, 2024

In this issue, we take a closer look at the prickly question of Biden's age. How will these concerns about Biden’s age shape the course of the election? The results from our investigation are below.

Last week, we published a Bi_Focal issue on the state of US Presidential Election polling. We explained how we're improving our polls to correct for unusual biases we've found in survey samples - including levels of social trust and vaccination rates. In our view, these survey panel skews and non-response patterns means there is a chance that current polling is underplaying the Democrats. Using this refined sampling and weighting methodology, we conducted our own swing state polling in Michigan, Pennsylvania, Arizona, Georgia and Nevada. You can check it out the results and our write-up here.

In this issue, we take a closer look at a particular dimension we probed in our polls -- the prickly question of Biden's age. A recent NBC poll found that 62% of voters have “major concerns” about his fitness for office. And earlier this month, a report by Special Counsel Robert Hur claimed that Biden’s “memory was significantly limited”. Trump often makes similar slips himself, but his vigour on the campaign trail is in great contrast to Biden. He just physically looks so much more energetic, and in politics looks make all the difference. How will these concerns about Biden’s age shape the course of the election? The results from our investigation are below.

Overall, we find that:

  1. Concern for Biden's age is high but unevenly distributed across different groups
  2. The issue with real potential to drive Democrat defection is inflation and the cost of living, not Biden's age
  3. Biden's substitutes bench is vacant, though low levels of awareness means Newsom and Whitmer - the next two closest contenders - still have room to define themselves to the electorate

The polling and analysis contained in this issue was first published by UnHerd ( You can read the original article here.

Who cares?

We found that Americans are far more concerned about Biden’s age than Trump’s. Half of respondents (49%) say they are “very concerned” about Biden, almost twice as many as for Trump (26%). Meanwhile, 38% of respondents are not concerned at all about Trump’s age — compared with just 14% for Biden.

Figure 1: Concern for Joe Biden / Donald Trump's age, all respondents
unnamed (16)
Source: Focaldata polling, n = 5004 in Michigan, Wisconsin, Pennsylvania, Georgia, Arizona, Nevada, fieldwork 17 - 23 Jan 2024

It’s not just Republicans who are concerned about Biden’s frailty — Democrats are too. You can see below the results broken down by how Americans voted in 2020. As one would expect, Republican voters are most worried about Biden’s age, and almost half of those who did not vote for either party are “very concerned”. Morale is also low among Democrats: nearly three-quarters (74%) of those who voted for Biden now have concerns about his age, and one quarter (24%) are very concerned about him.

Figure 2: Concern for Biden's Age, by 2020 Presidential Vote
Screenshot 2024-02-23 at 07.26.36
Source: Focaldata polling, n = 5004 in Michigan, Wisconsin, Pennsylvania, Georgia, Arizona, Nevada, fieldwork 17 - 23 Jan 2024Source: Focaldata, n = 5004, Fieldwork: 17 - 23 Jan 2024

This could create a problem for the Democrats, who are gearing up to fight a close defensive election. Biden is defending leads of under one percent in several states — and in these swing states, every point counts. He needs as many of his 2020 supporters as possible to back him again. That 24% of those who voted for Biden last time are now “very concerned” about his age is a bad omen for his campaign.

Though if we look in more depth at the figures, we can see that some Americans care more about his age than others: older people, white people, and men tend to be more concerned, while black respondents are likely to be less so.

Figure 3: Concern for Biden's age, by demographic group
Screenshot 2024-02-23 at 07.29.33
Source: Focaldata polling, n = 5004 in Michigan, Wisconsin, Pennsylvania, Georgia, Arizona, Nevada, fieldwork 17 - 23 Jan 2024

Biden's Achilles Heel?

The American people might be concerned about Biden’s age, but come election day how important will that actually be? How many votes does Biden really stand to lose (or protect)? People’s motivations to vote are often difficult to tease out, since concern about one issue is often not enough to actually switch someone’s vote in the polling booth.

That said, if voters were to become more concerned about Biden’s age, how would that effect the election? Some Democrats will remain loyal no matter what — their commitment to, let’s say, climate change will outweigh their unease about Biden’s competency. Others will have already made up their minds to desert, perhaps because of their experience of rising prices under his presidency. But some voters are on the fence, open to persuasion by further evidence of Biden’s frailty or aggressive Republican messaging.

The way to get at underlying motivation is to study how many different factors relate to vote intention, using a regression model. Last time, we did just that to understand why 2020 Democratic voters are not intending to vote for Biden this time around. Here are the results. As you can see, concern about Biden’s age is an important factor, but it's far from the most important.

Figure 4: Regression outputs, Biden defectors
Screenshot 2024-02-23 at 07.36.38

One of the neat things about using these models is you can use them to run simulation experiments. The model captures how all the factors interact. So we can simulate people becoming more concerned about Biden’s age, feed the data to the model, and see what happens. The results are often unexpected.

In this case, the model was re-fit to include each step on the 4-point scale from ‘not at all concerned’ about Biden’s age to ‘very’ concerned’ as a predictor. We then randomly sampled a subset of Democrat voters, who had their scores increased by one point: someone ‘slightly concerned’ became ‘moderately concerned’, etc. (These proportions are on the horizontal axis below.) Then this new data was fed back into the model, to see how many Democrats would likely defect from Biden in that particular scenario.

Figure 5: Simulation of impact on vote intention based on shifts in issue importance (Biden's Age and Cost of Living)
Screenshot 2024-02-23 at 07.44.06

And as you can see from the blue points on the graph above, our experiment had surprising results. As Democrat concern for Biden’s age increases, the proportion of defectors goes up — but only slightly. Even if 90% of 2020 Democrat voters were to increase their concern for Biden — something that would only happen after a truly shocking gaffe — we would still only expect 2% more people to consider defection than do already.

We also re-ran the same experiment, but this time with concern over the cost of living. Respondents had also been asked which party they thought would handle the cost of food and energy better, on a scale Better by Democrats - Same by both - Better by Republicans. We simulated people shifting one point along this scale, in the same way as we did for concern about Biden’s age.

When we analysed Democrat concern over the cost-of-living crisis rather than Biden’s age, the results looked very different. As you can see from the orange points, shifting opinions on the cost-of-living crisis had a far greater impact on defections. If Biden wants to win the hearts of swing voters, it is the economic issue he ought to address — even though Republicans will do their best to distract him with jibes about his age. That said, you can see why Biden's age might be the preferred target of Republicans nevertheless. Biden can fight an election on the cost of living, but he can't do anything about his age.

Biden's substitutes?

If the Democratic party is having any second thoughts about Biden, it’s a little late. Registration for the nomination has closed in the majority of states, so it would be impossible for a challenger to beat him in the primaries. The only possibility would be for Biden himself to stand aside, something that he’s suggested he has no intention of doing. The possibility of a genuinely brokered convention would be astonishing.

But would it help the Democrats if Biden stood down? And would more youthful candidates have an advantage? In the same swing state polls, we asked if people would vote differently if one of two Democratic “rising stars”, Gavin Newsom, the governor of California, or Gretchen Whitmer, the governor of Michigan, stood against Trump. As we can see from the results on the sanky diagram below, which plots out the various scenarios for each candidate vs. Trump, there is very little movement. It appears that many people are not familiar with either Newsom or Whitmer. Each is an unknown quantity, and still has an opportunity to redefine themselves for the American public.

Figure 6: Sankey diagrams, different candidates vs Trump  
Screenshot 2024-02-23 at 07.48.41
Source: Focaldata polling, n = 5004 in Michigan, Wisconsin, Pennsylvania, Georgia, Arizona, Nevada, fieldwork 17 - 23 Jan 2024

When we look at respondents who do recognise each candidate, the Democratic and Republican voting blocs are almost unchanged compared to a Biden v. Trump run. Whitmer outperforms Newsom, but that is only because she is governor in Michigan, one of the six states polled here, and does extremely well there. Newsom and Whitmer do convince a handful of those who say they “don’t know” in a Biden v. Trump election — but the figures are close to the margin of error for a poll of this size.

Looking at the state-by-state results below, we can see Biden’s relative strength among non-white voter groups. Newsom and Whitmer underperform Biden in the heavily non-white states of Arizona and Georgia, and Whitmer fairs similarly poorly in Nevada, where Newsom is helped by being governor of a neighbouring state. And indeed, Biden has long been popular among non-white voters, as he was perceived to be supportive of Barack Obama while vice president.

Figure 7: 2020 US Presidential Vote Intention under different Democrat candidate scenarios, by state
Screenshot 2024-02-23 at 07.51.58

What we can draw from all this is that, while Biden’s age is a real concern, it seems not the sole decisive factor in the 2024 election than much public commentary suggests. It may make for a less sensational headline, but the current President’s record on the economy and cost-of-living crisis will be the key determinant come election day — not his age. And should he decide to stand down, there may not be enough time to transform either Whitmer or Newsom into a strong, alternative presidential candidate capable of beating Donald Trump and so perhaps all eyes should rest on our next analysis — that of Kamala Harris — the most likely candidate by far to succeed the President, should he step down.


Focaldata online polling of 5,004 respondents in Michigan, Wisconsin, Pennsylvania, Georgia, Arizona, Nevada. Fieldwork was carried out between 17/01/2024 and 23/01/2024. Data is weighted by age, gender, education, race, Hispanic identity and state-level vaccination rates

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Feel free to check out our previous editions of Bi_Focal:

  • Last week's edition on US Presidential Election polling, the electoral college vote map and what it all means for Biden
  • Our two-part edition on the rise of Reform, and the shape of public attitudes on social and economic issues, available here (Part I) and here (Part II)
  • A new theory of "elastic seats", a defining feature of pivotal areas with large variation in voter support over time - link here
  • Our MRP of the Voice referendum in Australia last October (we were one of the closest pollsters to the final vote tally) - link here
  • Our (now year old) stress test of predictions about a Labour landslide -- still valid a year on, we think! -- link here

Finally, if you or anyone you know regularly run polling, we'd be happy to run a free couple of questions for you -- we'd love to demonstrate the speed of our platform and showcase the technical capacity of our research team.

For the above, or if you have any thoughts or feedback, please hit reply or email me at

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