But what it is ain't exactly clear.
There has been a consistent - remarkably consistent - pattern of primary polling consistently undercounting Nikki Haley's support in the primaries. Part of the reluctance of pollsters to really address this comes, I think, from failing to look at Trump as a de facto incumbent. Off the top of my head, the last time an incumbent president lost, then ran again, was Grover Cleveland. That was well before polling existed. So pollsters are really struggling with how to model a primary electorate where you have a de facto incumbent (Trump) who is not the actual president.
Josh Marshall tries to make some sense from the general polling landscape, but one observation he makes that I think is important when looking at polling right now is that a LOT of polling is a referendum in March on Joe Biden. Now, I am on the record with thinking that Biden is doing a great job, with the exception of Israel, and even there, I think my disagreement is a matter of degrees rather than a difference of principle. However, the "vibes" are bad and Biden takes the brunt of that as president.
In a fundamentally uncontested primary, Biden is racking up huge wins against Generic Challenger and a small but real protest vote. Trump is also running against Generic Challenger in Haley who is a bog standard Republican in a lot of ways: she's anti-abortion, pro-tax cut, pro-deregulation. The fundamental difference between someone who voted for Haley and someone who voted for Trump is whether they believe the 2020 election was legitimate.
If "the GOP is a failed state and Trump is its warlord" then a consistent third of Republicans are in revolt against the warlord. This also fails to capture the independents, including (often but not always) GOP leaning independents. In a closed primary, if you still have Trump facing a considerable revolt, that is fundamentally a revolt over January 6th and Trump's anti-democratic agenda.
Elliot Morris at 538 has a breakdown of why polling primary voters is hard. One thing he notes is that getting people to respond at all is hard, but especially now. Here's his take:
My theory is that most of these primary polls pulling samples of voters from voter registration lists are missing moderate crossover partisans and first-time voters. Additionally, we know that people who are highly motivated to participate in polls (the "weirdos") also happen to be the most politically and ideologically extreme Americans. That's a recipe for polling bias in primaries, where weighting to party, past vote and polarized demographic benchmarks does not control for the partisan consequences of overrepresenting politically engaged Americans.
That highlighted bit is key. The most polarized, ideological voters in the country are Trumpists and Biden's Leftist critics. However, we also know that the new Democratic coalition includes a LOT of college educated voters, who tend to vote in "off" year elections - this has been the go-to explanation of why Democrats have outperformed since 1/6 and Dobbs. College educated voters tend to be frequent and engaged voters, but they are also not necessarily the sort of engaged ideological voter that Morris is describing.
Biden's path to victory absolutely runs through winning the normie voter. We know Trump's cultists will crawl over molten lava to vote for their Mango Mussolini. We also know that in a perfect world every single Democrat and Democratic leaning voter would prefer that Biden were a decade younger. However, we also can see that Trump has real liabilities even within a normally compliant party.
Here's the most important thing, I think, to look at. Haley has suspended her race without endorsing. There are still more primaries to come. She will still be on the ballot. How many Republicans will still vote for her out of protest over Trump's insurrection? It's not Dobbs that has Republicans upset (maybe a few, but not 30%), it's Trump's criminality both on 1/6 and <gestures wildly at everything>.
Yesterday on Twitter, Nate Silver - who's on a "Joe Biden is old and losing" jihad - flagged Biden saying that "his last five polls showed him winning." Silver said this represented a complete misunderstanding of what the polling was saying and showed the public polling that has shown Biden to be consistently a few point behind. Except Biden said "his polling" not the Times or Fox or freaking Rasmussen. "His". Unless he was committing a gaffe, that suggests that their internal polling is showing something different than the public media polls.
Our wretched cable nets continue to post things like "85% of Trump voters would still support him if he was in jail." Of course they would. It's a cult!
Trump won't win by winning his cultists, and there is some evidence that he is really struggling to hold down even what few normie Republicans still exist.