Why Biden is underperforming Democratic Senate candidates

It is certainly not unheard of that there would be a difference between a state’s presidential and Senate vote, though the practice is a lot less common than it used to be. In this case, though, the split we see in current polls appears to be less a sign of Biden’s relative weakness than it is a sign of Lake’s. That pattern holds true in other swing states where Biden lags behind his party’s Senate candidates.

If we plot the margins in the Arizona presidential and Senate polling released by CBS this weekend, we see that, across demographic groups, Biden’s margins are worse than Gallego’s.

See the diagonal line below? Anything above that line indicates that Biden is doing better with the group than Gallego. Anything under the line indicates that Gallego is doing better. And all of the dots are below the line. Even among Democrats, Biden (plus-78 over Trump) is doing worse than Gallego (plus-85 over Lake).

The black “overall” dot above is in the lower-right quadrant: Trump is leading Biden (so right vs. left) and Gallego is leading Lake (so lower vs. upper).

But Biden and Gallego get about the same level of support across the state. Biden is at 47 percent and Gallego is at 49 percent. The difference is on the Republican side, where Trump gets 52 percent to Lake’s 36 percent. Just to reinforce the point: thirty-six percent!

Lake ran for governor in 2022 and lost. Her response was Trumpian, insisting that the results were suspect. This does not appear to have further endeared her to Arizonans.

If we compare the Biden-Gallego levels of support with the Trump-Lake ones, we again see an imbalance. Biden tends to have less support than Gallego; the dots are mostly on the left side of the vertical dividing line on the graph below. Trump has much more support among demographic groups than Lake; the dots are well above the horizontal dividing line. (The overall value here overlaps with the one among White Arizonans.)

We saw similar top-line numbers from the Siena College poll, conducted for the New York Times, which was released last week. In that poll, Biden did slightly better with Democrats and younger voters than Gallego, but he did worse overall.

In that poll, Biden did better than Gallego with those Democrats and younger Arizonans. Trump did better than Lake with every group except Democrats (where he got the same level of support: 7 percent).

The Times poll included similar questions for the races in Nevada, Pennsylvania (in a poll co-sponsored by the Philadelphia Inquirer) and Wisconsin. In each state, Biden underperformed the Democratic Senate candidate (again illustrated with the dots sitting under the diagonal line).

And in each case, Biden generally got lower levels of support overall and among demographic groups than did those Senate candidates.

This dynamic makes some sense when we consider the dynamics of these four races. Biden is not very popular nationally and the presidential results in these states in 2020 were close, and in Nevada, Pennsylvania and Wisconsin, the Republican candidates are challenging incumbent Democrats who are presumably better known. Even in Arizona, Gallego has the advantage of holding a seat in the House — probably a better launchpad than being a bad-sport losing candidate for governor.

What this suggests, particularly in the latter three states, is that the Republican candidates have room to grow as the campaign unfolds and both sides start pouring money into TV spots. As Election Day gets closer, they’re more likely to catch up to Trump’s levels of support than Trump is to descend to theirs.

In other words, while it’s still fair to say that the CBS poll offers good news and bad news for Democrats, the bad news seems a lot more stable than the good news. There and in the other swing states, it seems more likely that the good news for Democrats will flip than it does that the bad news will.