House Democrats are plainly scared of impeachment. Speaker of the House Nancy Pelosi told The New York Times last weekend that she worried Democrats would get bogged down in an impeachment proceeding, and the only way to get President Trump out was to nominate a bland moderate in 2020.

She slightly changed her tune Wednesday, saying that Trump keeps "making the case" for impeachment" and that "he's becoming self-impeachable." It's unclear what "self-impeachment" could entail, but as yet Democrats have not taken any concrete steps on the matter.

So let's lay out carefully the substantive and political case for convening an impeachment inquiry committee.

On just what is publicly known, Trump has unquestionably committed impeachable acts. No president has ever before maintained a vast business empire while in office — and he is directly using the White House budget to enrich himself. He's forced the Secret Service to rent his own golf carts, put himself and his family up in his own fancy hotels, and funneled vast sums of public money into his own pockets through his Mar-a-Lago estate — where he promptly doubled the membership fee upon taking office.

The Constitution plainly forbids the president profiteering off his office. Article II, Section 1 states that during a presidential term, "he shall not receive within that Period any other Emolument from the United States, or any of them."

Trump has also accepted huge payments from foreign governments. Reuters reports that at least seven foreign governments rented luxury condos in Trump's New York hotel — without receiving congressional approval. This also plainly violates the Constitution: Article I, Section 9 states that no one holding an "Office of Profit or Trust" in the U.S. can "accept of any present, Emolument, Office, or Title, of any kind whatever, from any King, Prince or foreign State" without Congress' consent.

Trump also plainly attempted to obstruct justice in the Mueller investigation — only failing because his subordinates largely failed to carry out his orders. He is arguably obstructing justice again right now, by ordering his associates to disobey congressional subpoenas (indeed, refusing subpoenas was one of the articles of impeachment against Nixon), refusing a clearly legal demand for the House to see his tax returns, and claiming executive privilege over the entire unredacted Mueller report.

Now, according to United States vs. Nixon, there is such a thing as executive privilege (particularly to "protect military, diplomatic, or sensitive national security secrets"), but it absolutely beggars belief that it would apply in this case given that Trump himself has written that the report shows "No Collusion, No Obstruction, Complete and Total EXONERATION."

Oh, and let's not forget that, while in office, Trump personally repaid his former lawyer Michael Cohen for bribing a porn star to keep quiet about an affair she had with Trump. And even all that is still leaving quite a lot out! As Hunter S. Thompson wrote about Nixon, Trump is "so crooked that he needed servants to help him screw his pants on every morning." No president has ever so obviously deserved impeachment.

This brings me to the politics. For starters, an impeachment inquiry is a valuable process: a committee holds hearings, brings in witnesses, gathers evidence, and constructs a case. National media will surely give it close attention, especially if the committee has national stars who can ask sharp questions and create some drama. Finally, if and when the committee draws up articles of impeachment, this creates a handy document full of evidence and references to prove the case. And in terms of investigating Trump's sprawling corruption, an impeachment inquiry is a handy way to keep it all together and organized. Nothing is outside its scope.

It's true that the Senate is virtually guaranteed to not vote to convict (which requires a two-thirds majority). This is what happened to Bill Clinton — which is probably a lot of why top Democrats are so hesitant to try. When Clinton was impeached, his popularity shot up, and he escaped conviction. But this was almost certainly because of the accurate perception that Republicans were trying to get rid of him on a ginned-up pretext (though the Lewinsky scandal was a genuine abuse of power, to be sure).

Nixon, on the other hand, unquestionably deserved to be impeached, and his popularity plummeted as the Watergate investigation proceeded, falling from over 60 percent to 24 percent over about a year and a half. Conversely, the percentage of Americans thinking he should be removed from office steadily increased, going from 19 percent to 57 percent over that same period.

Now, this isn't the 1970s either. Americans are much more polarized today, and Trump's base of perhaps 40 percent or so will likely never abandon him. But impeachment proceedings can still serve as a powerful political weapon. If Democrats can focus attention on the top two or three stories that are simplest and most scandalous, and repeat them over and over during the proceedings, that helps create a narrative that can stick in the minds of voters. This will both excite the Democratic base and demoralize Republicans, who will struggle to overcome the cognitive dissonance of President "Drain the Swamp" having both hands deep in the federal till. (Meanwhile, presidential candidates can continue to focus mainly on attractive policy to win votes.)

It will also show the country that Democrats are willing to stand up to defend American democracy even if the entire Republican Party will let Trump get away with anything. It shows spirit, determination, and confidence — things that attract voters in times of uncertainty.

Finally, it's worth remembering that impeachment is constitutionally obligated. The separation of powers only works if the other branches actually defend their prerogatives. Every one of the Founding Fathers would be horrified that this corrupt, incompetent oaf is still in office. Retreating into learned helplessness and hoping the voters will rescue the country from Trump will only embolden his assault on American democracy.