To impeach Trump the Democrats would effectively have to have a super majority in the House and Senate and those members would all either have to be hard line leftists (the Sanders, Ellison, and Warren types) that utterly hate Trump or Trump would have to do something so severe that it would piss off enough Republicans to join the democrats to make up for the gap. It would have to be undeniably confirmed Trump and his team colluded with Russians and did something extremely shady like sell top secret info. and tech to Russians or gave campaign information to the Russians to attack Hillary Clinton before that could happen.
If they tried to impeach Trump anytime soon it would be like the Republican attempt to impeach Clinton in the late 1990's, they would just end up the butt of late night television jokes and give the opposition something to use against them for the next 20 or so years.
And the real problem is, what can you impeach him FOR?
To quote the Constitution:
"The President, Vice President and all Civil Officers of the United States, shall be removed from Office on Impeachment for and Conviction of, Treason, Bribery, or other high Crimes and Misdemeanors"
Treason's out. Trump is a big advocate of the US, always has been. Simply disagreeing what he's doing to serve the interest of the US does not qualify as the legal definition of treason, and so long as he's not doing, to again quote the source:
"Treason against the United States, shall consist only in levying War against them, or in adhering to their Enemies, giving them Aid and Comfort. No Person shall be convicted of Treason unless on the Testimony of two Witnesses to the same overt Act, or on Confession in open Court."
Basically, trying to get this to stick would be laughable.
Bribery is also out....I mean, come on, what could you realistically bribe a guy like TRUMP with?
So that leaves anything else idiots like Wu hope can stick, so let's examine those other cases.
Andrew Johnson was the first president an impeachment was attempted, and it was a nakedly political attack, with most of the case being based on a very shaky piece of congressional legislation subsequently declared unconstitutional by the Supreme Court (the Tenure of Office Act, which was illegal due to violating the separation of powers between the executive and legislative branches of government) .
Nixon was the next one it was attempted on, and while he resigned before it could be implemented, that was considered legitimate because he was found guilty of abuses of power that were injurious to the US, such as abusing federal agencies to bury evidence of the crimes of others and being an accomplice to the coverup of those crimes even if he had no direct part in it.
Clinton was the next party this was attempted on, and it was partially political, partially based on acts that were scandalous but not actually impeachable offenses, so it ultimately fizzled out because nothing deemed an abuse damaging to the United States as a whole could be proven.
With that in mind, I'd like to know what Wu thinks will work here. Just because Trump has the political grace of an elephant trying to waltz is not the definition of a traitor. Just because Trump is his political enemy doesn't mean he's guilty of treason, and until he commits an actual abuse of power or an actual, legally defined offense for which he can be charged and convicted, then all Wu's got is daydreaming about it.