In Monmouth's report, though, there's a line that's particularly worth pointing out. "Trump continues to draw his support evenly across the ideological spectrum," it reads, "including 35% of very conservative voters, 36% of somewhat conservative voters, and 36% of moderate voters."
If the Republican party once had lanes, Donald Trump is their Kramer, driving his jalopy down the highway with a barrel of black paint.
There are a lot of reasons that Trump polls so well, including that he is an actual celebrity with wide name recognition. He's seen as a legitimate outsider, meaning that voters aren't predisposed to categorize him. And his rough-hewn policy priorities ("Win." "Build a wall." "Beat ISIS.") make it hard for any faction to claim or reject him.
We can contrast his support along the ideological spectrum with two candidates who do fall into established Republican lanes. If we look at Quinnipiac University polling since before Trump's rise, we can see the base of support for Ted Cruz -- conservatives -- and Jeb Bush -- moderates. In every poll (or almost every poll) they do substantially better with that base than with the opposite end of the spectrum, and than with Republican voters overall.
Contrast that with Trump.
It's as hard to know why Trump's support is so even as it is to nail down why Trump has so much support at all. The risk this offers to Trump is that if his support drops in one group, it may drop in all of them -- but the benefit is that he's not propped up by one pillar, as was Ben Carson, whose campaign deflated once conservatives turned to Cruz.
Iowa is in 12 days, at which point these numbers will probably change rapidly. Or maybe they won't. Maybe the future of the GOP is this one wide, luxurious lane, allowing the Trump steamroller easy passage.