This interesting development gets at several issues worth attention. First, Nadler is really trying to get Pelosi to go for impeachment. Pelosi doesn't want to. A while back, I commented that the real key to whether or not Pelosi can stop the impeachment proceedings from happening is whether or not she can hold back Nadler, and that's getting harder for her.
The more important matter here is the strategy. This is worth some elaboration. Look, folks, you know where I stand on impeachment. It'll backfire, just like it did on Republicans when they impeached Clinton. The '98 midterm was one of two midterm elections in modern history in which the president's party gained seats in the House (the other being 2002, when Bush 43 was still riding high on his 9/11 approval bump). However, there are multiple motivations for impeachment within the Democratic Party, and they are worth addressing.
1. The non-strategic impeachment. Plenty within the Democratic Party want to impeach Trump because he has committed impeachable offenses. And... yes. The courts haven't sided with the Democrats on emoluments because of the coward's ruling-- standing. That doesn't say anything about Congress's ability to impeach. That's before we get into obstruction or conspiracy. However, no sane prosecutor would ever bring charges when acquittal is certain, and only the dumbest prosecutor on the planet would indict knowing with absolute certainty that the jury will be rigged. That jury? It's called "the Senate." Bringing an indictment just because you know someone is guilty is not a rational act, when you have absolute, 100% certainty of acquittal in a rigged trial. Non-strategic. This isn't fighting the good fight. It's fighting a lost fight.
2. The WTF impeachment. There's a Representative with the coolest name in Congress, and some really atrociously bad ideas about what constitutes impeachability. Al Green. No, not that Al Green. That's why it's the coolest name in Congress. He tried to force a vote on impeachment proceedings because of those send-them-back tweets. Racism is really, really horrible. But is it a high-crime/misdemeanor? Um... no. Seriously, people. Get a grip. You also cannot constitutionally impeach Trump for being a dimwitted, semi-literate television addict or narcissistic sociopath. Are these horrible traits for a president? Arguably, the worst. But, they aren't high crimes or misdemeanors. 25th Amendment? Yeah, I'd argue, but that's a different process, and it ain't gonna happen.
3. The show-the-people impeachment. This one baffles me, but... they all baffle me, so that isn't saying anything, is it? The idea is that impeachment proceedings will shine a spotlight on how corrupt and horrible Trump is, and even though Trump will be acquitted in the Senate, the spotlight on Trump's corruption will help Democrats. Here's the empirical problem. Haven't we had plenty of spotlights on Trumpian corruption? a) It doesn't move opinions of Trump, because that's baked in, and b) there will continue to be the "witch-hunt" counter-narrative pushed by the GOP, which gets strengthened by a Senate acquittal, having already been strengthened by Mueller's performance last week.
Unless, and this gets at the new legal argument House Democrats are making...
4. By opening an impeachment inquiry, Democrats get a stronger legal argument to force the release of documents, force compliance with subpoenas, etc. That way, maybe new stuff gets revealed, and public opinion finally moves. See #3.
What's the problem with #4? There are several problems. First, anyone open to the idea that Trump is corrupt and that it matters already thinks that. There's nothing more to gain. Second, the idea that you can trust the courts at this point, where Trump is concerned... have you noticed the pattern with courts lately? This week, the SCOTUS sided with him on his border wall constitutional power theft. That Article I/Article II distinction on who gets to decide where money is spent? Yeah, that doesn't really limit Trump so much, according to the courts. In DoC v. New York, they put a stop to the citizenship question because Trump couldn't even come up with the thinnest veneer of a reason, but all Trump needs is a micron or so because they really want to side with him.
Translation: don't have any confidence that the courts will side with the Democrats, impeachment proceedings or not. Have absolute, 100% confidence that Gorsuch, Kavanaugh, Thomas and Alito will side with him, and that any court fight will get dragged out, and even if Roberts sided against him...
Andrew Jackson, anyone? What would it take for Trump to pull an Andrew Jackson? I doubt he'd go that far to keep Hope Hicks from testifying, knowing that she'd just stonewall, so why bother? If a SCOTUS ruling said she had to testify in August of 2020... so what? It'd be a joke of a hearing, after a year of pointless legal fights.
On the other hand, would Trump pull an Andrew Jackson to keep his tax returns secret? Anyone want to place bets on that?
At the end of the day, I just don't see the gain here. The fundamental problem remains this: a political system in which corruption is limited requires bipartisan consensus that corruption should be limited, and that each party has a limit to the amount of corruption it will tolerate on its own side. Once this ceases to be the case, a party in power plagued by corruption rots the system to a point at which it cannot recover.