This is nice, and it’s not the only poll this week to find Americans rightly suspicious of what Joe and Hunter Biden were up to. But watching Trump risk impeachment to try to blow up Grandpa Joe at this stage of the race is like if Obama had bet his presidency on taking out Jeb Bush circa July 2015.

You don’t need to go nuclear on a frontrunner who isn’t really the frontrunner anymore.

According to USA Today/Ipsos, 42 percent say there are good reasons to investigate the Biden’s Ukrainian activities versus just 21 percent who say there aren’t. Even a quarter of Democrats agree. That’s the good news. The bad news is that skepticism about the Bidens’ shadiness doesn’t seem to be undercutting interest in impeachment. Or in removal:

Americans by a 45%-38% plurality now support a vote by the House of Representatives to impeach President Donald Trump, a USA TODAY/Ipsos Poll finds, as allegations continue to swirl around an embattled White House.

By a similar margin, 44%-35%, those surveyed say the Senate, which would then be charged with holding a trial of the president, should convict Trump and remove him from office…

Americans have long been wary of impeachment. A USA TODAY/Suffolk University Poll taken in June – months before the formal impeachment inquiry was launched last week – found opponents outweighing supporters by nearly 2 to 1, 61%-32%…

One more warning sign for Trump: Nearly two-thirds of Republicans say there isn’t enough reliable information to decide whether he should be impeached. That leaves open the possibility that dramatic disclosures and persuasive evidence could convince some in Trump’s own party that impeachment is warranted.

From a -29 net split on impeachment in June to a +7 net divide now. Thirty-six points is a big turnaround. The most ominous number is that last one, though, showing even many Republicans remain willing to reserve judgment for now. USA Today notes at one point that “just” 17 percent of Republicans currently support impeachment, but 17 percent isn’t negligible on a question as momentous as this. (Harry Enten notes that the sort of moderate Republicans who are more likely to support impeachment are also overrepresented in key Rust Belt states.) It’s not a huge deal for Senate Republicans to find 45 percent of the public in favor of impeaching, as virtually any hotly contested partisan issue in 2019 will draw at least that much support via one party or the other. The noteworthy figure is the 38 percent in opposition; that number “should” be higher considering that Trump regularly registers a job approval in the low 40s. There’s a small but potentially dangerous GOP minority here that’s not ready yet to view this through the familiar partisan prism. Maybe yesterday’s Adam Schiff revelation will get them there.

But then, maybe this morning’s Trump statement on the White House lawn will drive them further away from it.

Speaking of Trump’s job approval, there continue to be some good polls for him amid this Ukraine clusterfark. Rasmussen (which is usually good for him) has him at 47 percent today. And the Hill/Harris X has him up to 49 percent, his single best mark of the year. Is that the smoking gun that impeachment is beginning to backfire on Democrats already? Probably not — for the moment, the RCP poll average shows Trump having *lost* a few points since a surge in late September.

FiveThirtyEight’s tracker also sees a loss of around two points or so over the past few weeks. That’s not disastrous: Trump’s RCP approval of 43.2 percent today is right in line with his average approval for the past 18 months. He had been rising in late September, though, even touching 45 percent for a day before the Ukraine stuff began to bog him down. If you want to see some real poll erosion, go look at the trend in Biden’s polling against Elizabeth Warren. He’s at 26.2 percent today, which is close to his worst number in the primaries this year; Warren, meanwhile, is at 24.0 percent, easily her best number of the campaign. She’s gained seven points in the past 17 days and has led in two of the last three national polls taken. We’re closer than we think to a political reality in which the Ukraine matter, which was supposed to be a weapon exclusively for the right to use against the left, becomes a weapon exclusively for the left to use against the right.

Here’s Biden warning Trump yesterday before a throng of supporters, “You’re not going to destroy me.” True. Elizabeth Warren’s going to do it. Exit question: If Trump is telling the truth when he says that his interest in Biden’s Ukraine conduct is all about exposing government corruption, not accruing political advantage against an electoral opponent, then we should continue to hear from him frequently about the Bidens and Ukraine long after Grandpa Joe’s polls tank and he becomes an also-ran in the race, right? Let’s see if that happens.