American politics is now, in large part, a fight about whether or not Donald Trump will be impeached.

No one is saying it explicitly, but these are the stakes in the Russia controversy and its spinoffs and in the 2018 midterms. If Democrats take the House with anything like a comfortable majority, they will be hard-pressed to resist their base’s drive to give Trump a mark of dishonor shared only by Andrew Johnson and Bill Clinton.

Presidents have been hated by the other side before, but rarely with this sort of intensity and immediacy. With the exception of Abraham Lincoln (seven Southern states seceded before he took office), it usually takes time for critics to work up a good, unbridled loathing. Herbert Hoover had to preside over the beginning of the Great Depression. Richard Nixon had to bomb Cambodia and get embroiled in Watergate. Donald Trump just had to show up.

The left’s anti-Trump rhetoric has been catastrophist from the beginning. The initial travel ban represented a constitutional crisis. So did the firing of acting attorney general Sally Yates. And so, of course, did the cashiering of FBI Director James Comey.

Harvard law professor Laurence Tribe, once frequently mentioned as a potential Democratic Supreme Court pick, wrote a piece a couple of weeks ago titled “Trump Must Be Impeached.” Must doesn’t allow for wiggle room. Tribe maintains that “impeachable offenses could theoretically have been charged from the outset of this presidency.”

Left-wing New York Times columnist Charles Blow writes about “the critical and increasingly urgent question for many: Will Trump be impeached — or indicted — and when? The anticipation has produced a throbbing anxiety. There is so much emotional investment in Trump’s removal that I fear that it blinds people to the fact that it is a long shot and, in any case, a long way off.” Yes, impeachment might have to wait till early 2019. Who has the patience?

It may be that Democrats don’t take the House, or even if they do, they pull up short on impeachment. A House impeachment vote would almost certainly only be a symbolic gesture. The chances of getting the two-thirds of the Senate necessary to remove Trump from office are close to nil, unless there’s an offense that collapses his support among Republican senators.

House Minority Leader Nancy Pelosi has been cautious, saying that impeachment has to be a factual, not an emotional, project. But it may be that impeachment becomes de facto Democratic orthodoxy whether the party’s leadership likes it or not. The grass-roots group MoveOn.org has already called for it (and before Comey’s testimony).

What would Democrats impeach Trump for? This is a question of mere details. They will surely find a case somewhere amidst the feverish allegations of obstruction of justice, abuse of power and violations of the emoluments clause.

There’s always a danger of overreaching. Democrats in Wisconsin ended up pushing swing voters toward Gov. Scott Walker with their all-out resistance and attempted recall. Republicans paid a price impeaching Bill Clinton in the 1990s, even if they still won the presidency two years later.

Until further notice, though, any point scored against Trump in the Russia controversy or any political gain by the Democrats has to be considered another step toward impeachment. The White House needs to realize the gravity of the situation, and so should the president.

Trump’s boast that he would be willing to contradict James Comey under oath is, if sincere, incredibly reckless. This isn’t like playing cat-and-mouse games with reporters in his days as a celebrity businessman, or jousting with Rosie O’Donnell in the media. Any misstep — any contestable claim or outright falsehood — can and will be used against him in an impeachment proceeding.

Perhaps we ultimately won’t get there, because cooler heads will prevail. But who, having watched American politics over the past 18 months, has any confidence in that happening?

Rich Lowry is a syndicated columnist. He can be reached via e-mail at: comments.lowry@nationalreview.com.