Vice President Biden’s announcement of his candidacy for president must be seen as the last stand of forces trying to prevent the Democratic party from descending in a power dive into a mighty bonfire of the far Left.

That party’s only plan of action since Election Day 2016 has been to attempt to destroy Trump, and that tactic survived even the complete dismissal of the Trump-Russia collusion canard and the declination of leaders of the Justice Department to accuse the president of obstruction of justice (for the reason that no ingredients for a prosecution existed).

The replacement tactic was to invent the argument that Special Counsel Mueller had invited the House of Representatives to consider whether there was a case for obstruction, which was all they needed to fill the calendar from now to the next election with antagonistic hearings with Trump-administration and Trump-entourage witnesses who would be taunted and baited and harassed as if being turned on a spit. The administration has announced that none of the House subpoenas will be honored, and no more administration witnesses will be permitted to appear.

Few press commentators seem to notice the pattern that has developed, of Mr. Trump’s enemies taking declarative positions in opposition to the administration and then being outmaneuvered. It was only a few months ago that the official Democratic position from Speaker Pelosi was that the illegal-immigration crisis was a “fake crisis made up by the president” and a border wall was “immoral.”

There was a government shutdown over funding for the wall. The president declared an emergency and took all the money he said he needed to build the wall amid Democratic howls of impending vengeance in the courts. The consensus seems to be that the administration’s legal case is a strong one and the courts may not be so amenable to litigious Democratic congressmen.

Attempted illegal entries across the southern border have soared; Obama’s homeland-security secretary, Jeh Johnson, has endorsed President Trump’s view; and even Tom Friedman of the New York Times, one of the president’s harshest critics, agrees that there is a crisis. He continues to attack the president for not producing comprehensive reform, though Mr. Trump has advocated substantial improvements to the immigration “system” (the quotation marks are Mr. Friedman’s). This will presumably await the next election.

In the meantime, the wall is being built. This was Mr. Trump’s most memorable election promise, and, according to polls, it’s the first priority of voters.

Now the promise, touted across the press for a febrile ten days following release of the Mueller report, for a profound examination of the virtues of impeachment of the president, while the scores or even hundreds of witnesses interviewed by the Mueller inquiry are recycled through the Schiff-Nadler baiting pits in the House Intelligence and Judiciary Committees, has also vanished.

The initial, customary cry of recourse to the courts has subsided, as the president has a strong case there also. President Eisenhower took a similar position opposite Senator Joseph R. McCarthy, and his witnesses had not been vetted and examined, as this president’s have. Messrs. Schiff and Nadler are in no higher category of legislative and judicial distinction than was McCarthy.

Mr. Trump is pushing the Democrats’ impeachment threat back in their faces. They can impeach (if they are insane), make an unpromising trek to the courts, or move on to the next source of confected outrage.

As is almost always the case, I was in some agreement with my esteemed friend Peggy Noonan when she wrote in the Wall Street Journal on Saturday that Mr. Trump might have got half of Washington on his side if he had made any overtures to it and shown any deference or even interest in the retired Washington establishment, which does have a collective influence in establishing the ambiance of the capital’s political community, which in turn is somewhat reflected in the press.

Peggy has the experience of President Reagan, who was dreaded and disparaged before he arrived, but who, as only he could do, charmed most of the Washington establishment. Something similar, in a much less hostile atmosphere, was achieved by President Eisenhower. But it never clicked for President Nixon, even when he dazzled Washington and the country with his achievements and made a conciliatory effort, all well before the Watergate debacle got any traction.

I am no authority on the inner workings of Washington, and I defer to those who are. But Donald Trump didn’t arrive in Washington as those others did, and he is the tip of the spear of much greater public discontent than those former presidents. President Eisenhower was a world historic figure before he took the oath. He had a mandate to end the Korean War and run a scandal-free government; he did that.

Richard Nixon was inaugurated president of a divided and angry country, and he addressed the sources of the unrest: He completed desegregation and avoided busing school-children into remote neighborhoods for court-ordered racial balance, and he withdrew from Vietnam while preserving a non-Communist government in Saigon. President Reagan had a mandate to reduce taxes, rebuild defense, and end the perceived appeasement of the USSR, and he did so.

Donald Trump’s right to govern has never been conceded by the Democrats or much of the press, and for the first six months of his term, the Republican congressional leadership seemed to be waiting to see if he really was likely even to serve out his term. I certainly am one of those who wish that the president would be more emollient at times, and perhaps more fluent.

The president, though, is a more articulate speaker than Truman, Eisenhower (though Ike’s verbal confusion was frequently deliberate), Johnson, Ford, Carter, and the Bushes. My suspicion is that if he had made peace offerings to the old Washington hands, it would have been scorned as the inelegant self-ingratiation of a preemptively compromised president, not as an olive branch from the incoming rightful leader.

We are where we are, and if Joe Biden isn’t the nominee, the Democrats are almost certainly going to go into the deep end and not be seen again for at least two years. Parties often rebuild themselves well after such total-immersion experiences, as the Republicans did after 1964, and the Democrats did after 1972. The sensible Democrats should not imagine that Mr. Biden is any world-beater, or that he is likely to win.

Mr. Biden’s launch was a fiasco, beginning with “I was thinking, in my mind . . .” (the usual locus for thinking), and he bobbled the whole question of being overly tactile with women. At least he didn’t grovel about it and continue his toe-curlingly awful apology tour in the footsteps of Kamala Harris and others.

And he didn’t really apologize to Anita Hill. The truth is, Clarence Thomas is a distinguished Supreme Court justice, and the Hill attack on him was as Justice Thomas described it, “a national disgrace . . . a high-tech lynching for uppity blacks.” Mr. Biden’s apology should be to the memory and family of Robert Bork, whom he and Teddy Kennedy defamed unforgivably when he was a candidate for the high court in 1987.

Mr. Trump’s policies are forcefully presented, but only a little right of center; Mr. Biden is wobbly, but no extremist. With the end of any notion of impeachment (unless the Democrats have an uncontrollable death wish), although there will be great election fireworks, American politics may be inching back toward normalcy at last.

CBLetters@gmail.com. From the National Review.