WASHINGTON — President Trump’s late decision to go all-out for accused sexual predator Roy Moore in Alabama’s Senate election has cost him greatly in terms of his own political credibility, and it has clouded his legislative prospects in dealing with the Congress controlled by his own party.

Instead of a Moore victory that would have triggered an embarrassing Senate ethics investigation into Moore’s fitness to serve, the election of Democrat Doug Jones will narrow to 51-49 the already slim Republican majority there. It could augur trouble for Trump’s contentious tax reform bill that heavily favors wealthy corporate interests at the expense of poor and middle-class workers.

The president’s personal push for Moore, ludicrously staged at a Pensacola, Florida rally just across the Alabama border, did nothing to shield or diminish his stamp on the candidacy of a man whose sexual behavior brought reminders of Trump’s own admissions.

The rally came at the time of the blossoming “#MeToo” movement of women speaking out against sexual assault and harassment, as the 2018 midterm congressional elections loom as a telltale weathervane for the 2020 presidential campaign.

Moore’s defeat in a Republican state that went heavily for Trump in 2016 challenged the president’s political savvy in backing him, as well as the reliability of his vaunted faithful, especially in the Deep South. It had already failed the same test in Virginia weeks earlier, where Trump’s favored gubernatorial candidate, Ed Gillespie, also lost.

The turnout in heavily black-voting Alabama precincts was critical for Jones. It likely was fueled by Trump’s frequent racial marks, as well as his observations after the earlier Charlottesville, Virginia street riots equating the behavior and motivations of neo-Nazis and with those of protesters against Confederate monuments.

Jones also won a majority of the Alabama white female voters, who essentially disregarded his openly defended support of legal abortion and Moore’s pitch that Washington elites looked down on his state and its citizens as a cultural backwater. Moore insisted, as did Trump, that Alabamians would decide for themselves who should be their next U.S. senator.

The repudiation of Moore, and by extension of Trump, amounted to a vindication of sorts for Senate Majority Leader Mitch McConnell. He had called on Moore to bow out of the race, and other Senate critics of the president who voted against the Trump legislative agenda also opposed him.

A conspicuous loser along with Trump was his former chief White House political strategist Steve Bannon. As head of the ultra-nationalist Breitbart News website, he went personally to Alabama, spoke for Moore and touted his candidacy online. It amounted to a continuation of Bannon’s campaign to wrest control of the Republican Party from the old party establishment that has already been rendered politically impotent by its own ineptness in the era of Trump.

All this outcome has resulted from the Trump decision to reward his first U.S. Senate backer of 2016, Jeff Sessions of Alabama, by choosing him as his attorney general. It created the vacancy that Moore sought to fill, but it now goes to Jones, derided by Trump as that “liberal Democrat” he didn’t want in the Senate.

The bad bet that Donald Trump made in Alabama may well have other political ramifications not to his liking down the road, as questions are raised about his efforts to undo aspects of the Obama domestic and foreign policy agendas.

The 24-hour news media and Internet discussions that now dominate American television, and occupy much of president’s daily waking hours, assure endless rehashing of the Alabama special Senate election and Trump’s role in it, as more doubts and questions are raised about his own tenure.

Meanwhile, he continues to tweet away, attacking Democratic Sen. Kirsten Gillibrand of New York for soliciting campaign contributions, and saying she “would do anything for them.” She responded by calling it “a sexist smear” and an “attempt to silence my voice,” while others professed to hear ugly innuendo in it.

Asked about it, White House press secretary and chief apologist Sarah Huckabee Sanders offered: “I mean, only if your mind is in the gutter would you have read it that way.”

Thus do partisan politics and personal insults meet the burgeoning “#MeToo” movement in the Trump presidency, with more of the same on both sides ahead.

Editor’s note: Jules Witcover’s latest book is “The American Vice Presidency: From Irrelevance to Power,” published by Smithsonian Books. You can respond to this column at juleswitcover@comcast.net.