But those same polls don't suggest doom and gloom for down-ballot Republicans just yet. And, in fact, there's real reason for GOP optimism that Trump won't ruin their year completely.
For one, the so-called generic ballot — i.e., whether people prefer a generic Democrat for Congress or a generic Republican — still favors Democrats by only a small margin: three points in both the Post-ABC poll and NBC News-Wall Street Journal poll, among likely voters. That same Democratic edge on the generic ballot is actually down from six points in last week's NBC-WSJ poll.
Put plainly, these generic ballots are unremarkable and don't suggest a big Democratic wave ahead.
Part of the reason Trump's woes might not have filtered down-ballot could be that a strong majority of people don't really associate Republicans with their party's presidential nominee. And many people also appear to dislike Clinton enough that they like the idea of a Congress that could keep her in check.
The Post-ABC poll includes a question about whether people think Trump represents the "core values" of the Republican Party, and a strong majority of likely voters say he doesn't — 57 percent overall.
The number includes a whopping 62 percent of independents. Just 27 percent of them think Trump does represent the GOP.
And the NBC-WSJ poll might be even more encouraging for Republicans, because it suggests a path forward for them. The poll asked whether registered voters would be more likely to support a congressional Republican who would be a check and balance on Clinton and Democrats, and 53 percent said they would. Just 40 percent preferred a congressional Democrat who would help Clinton pass her agenda.
And we've already seen some Republicans begin to employ this strategy — suggesting they should be elected in order to counterbalance Clinton. It's not pervasive at this point, but it would appear to be at least a semi-compelling argument for Republicans to make if they think Trump is a lost cause and they want to distance themselves from him.
It's also worth noting, to that point, that Clinton hasn't really pressed the case that Trump is representative of the broader Republican Party. Democrats, at this point, might wish she had.
As for the Post-ABC poll, it's possible that people might not think Trump represents the GOP but still decline to split their tickets. Ticket-splitting continues to decline in American elections, as our country becomes more and more polarized.
But we're also in a highly unusual election, in which a strong majority of people (and many more in Trump's case) don't like either candidate. Given that a strong majority dislikes Clinton, it's at least theoretically possible that people might be more willing to split their tickets if Clinton is headed for victory, as the NBC-WSJ poll suggests.
All of that said, even in the best-case scenario, it might not be enough for the GOP to salvage its Senate majority. That has been in jeopardy from the very beginning of the 2016 election cycle, thanks to a very tough map for the GOP. And we believe Democrats are narrowly favored to win the chamber at this point.
But as I wrote last week, the case for Democrats retaking the House was premised on the idea that Trump would prove an anvil tied to the ankles of Republicans across the country. I said at the time that we were still waiting for real evidence that this was true, and the newest national polls suggest it might not be.
The GOP shouldn't count its congressional majorities safe by any means at this point, but in an election that has tested all of our preconceptions about American politics in 2016, it's not unreasonable to think that a big victory for Clinton might fail to filter down to congressional Democrats — at least, as much as we're accustomed to.