A poll commissioned by a Republican consulting firm has found that any of former Vice President Joe Biden, former Rep. Beto O’Rourke or Sen. Bernie Sanders would beat Donald Trump in Wisconsin.

And Biden would beat Trump in Pennsylvania also.

The key details from Axios’ Mike Allen this morning:

Biden, Beto and Bernie all beat him head to head in Wisconsin ... Trump beats all three in Michigan ... Pennsylvania splits: Only Biden beats Trump there.

Wisconsin and Pennsylvania moving into the red was a key factor in delivering Trump’s win; had he lost just one other state, Hillary Clinton would have won as expected.

The survey comes from Firehouse Strategies, a GOP firm with strong ties to Sen. Marco Rubio, and 0ptimus. For that reason, it may be talked down by Trumpers and some Democrats as inherently biased.

However, the poll also “finds President Trump's approval underwater in Pennsylvania, Michigan and Wisconsin — vital states from his 2016 map that form Dems' most likely path to 270.”

That suggests that while the poll currently shows Trump beating all of the “Bs” in Michigan, there are some big signs of trouble here for Trump in key states. And if he lost all of Wisconsin, Michigan and Pennsylvania in 2020, he’d be finished.

This should in no way suggest that other candidates can’t perform at the same level as Biden, Beto or Bernie or that they should be granted an easier pathway to the Democratic nomination.

But it does give further hints about where Democrats’ strongest plays may be.

For my money, the Sanders result is more a function of name ID than anything else, and once attacks on Sanders began, he would perform less well in these places.

But Beto is generating a lot of the grassroots enthusiasm that President Obama used to propel him to two wins and is extremely charismatic.

And Biden has high name ID and an apparent ability to bring the Obama coalition back to life— which previously delivered for Democrats. Talk to some Trump voters, and even if they hate Obama, they still like Biden.

Maybe this survey bears some of this out, or maybe it’s just some Rubio consultants trying to stir up some trouble by making Trump look so weak and fringe that even Bernie Sanders can win in Wisconsin. A lot of Rubio people still hate that Trump bested their golden boy in 2016, rather than learning that Rubio’s more rigid adherence to conservative dogma (apart from on immigration) made him a non-starter for a lot of voters who may call themselves “conservative” but on issues are hardly in line with the Heritage Foundation or whatever other right-wing think-tank in Washington DC.

Whichever way you cut it, though, this poll is interesting as a single data point. Let’s see if it’s replicated elsewhere.