Roy Moore's refusal to bow out of Alabama's special election for a Senate seat is the latest demonstration of the diminished power of congressional leaders and other once-powerful institutions in Washington.

The Republican nominee, accused of sexual contact with a 14-year-old when he was a

32-year-old local prosecutor, brushed off calls for him to stand down as part of plot by establishment figures to "undermine this campaign" before the Dec. 12 ballot. Moore ignored the severing of financial ties by the National Republican Senatorial Committee for similar reasons.

He summed up today's environment in a fundraising pitch to supporters Friday morning: "I will NEVER GIVE UP the fight!"

Moore is right — it might be entirely up to him when or if he will ever give up the fight. The tools available to Senate Majority Leader Mitch McConnell (R-Ky.) and other Washington figures to drive Moore out of the race either no longer exist or have been rendered impotent by the rise of a new political structure. From the media to big corporations to Congress, public distrust has grown across the board and made it easier for outlier figures such as Moore to thumb their nose at the purported leaders.

"It's a distrust of institutions, all institutions," said Josh Holmes, a senior political adviser to McConnell. "There's just no deference at all in politics today."

That change has occurred rapidly. In 2002, then-Vice President Richard B. Cheney called Republican Tim Pawlenty on his way to announce his bid for the Senate and informed him that Norm Coleman would be the GOP Senate nominee. Pawlenty, Cheney told him, was running for governor, a message he relayed to his surprised supporters a few minutes later at his kickoff announcement.

The Minnesotans followed Cheney's orders, winning both races that year.

On Thursday evening, after The Washington Post's article on the accusation against Moore published, Vice President Pence's spokeswoman called the accusations "disturbing" and said, if true, would "disqualify anyone from serving in office." The next day, on Sean Hannity's radio show, Moore gave a long, sometimes contradictory explanation of the allegations, fully denying the accusation of sexual contact with the 14-year-old but leaving open the possibility that he had dated other teenagers.

[Senate candidate Roy Moore does not rule out that he may have dated teen girls when he was in his 30s]

It's one thing to dismiss McConnell. Like every congressional leader of this era, he is very unpopular. Just 25­ percent of Americans approve of his job performance, while 50 percent disapprove, according to a Post-ABC News poll released last week.

Among Republicans, McConnell's support is lukewarm at best. Less than 40 percent of "somewhat conservative" and "very conservative" Republicans approve of McConnell's tenure.

In such a conservative state as Alabama, it's no wonder Moore feels as though he can dismiss the Senate leader. Yet Pence and his boss, President Trump, both remain very popular in Alabama, with public polls showing the president's job performance liked by about 60 percent of voters.

If those two lean harder into trying to push Moore out, it might have more of an effect.

Then again, ask Roland Burris about his defiance of an incoming president and congressional leadership. The Chicago Democrat was appointed to fill the vacant Senate seat of then-President-elect Barack Obama in January 2009, but that appointment came from the indicted governor, Rod Blagojevich, who was accused, and later convicted, of trying to sell the appointment to whoever raised him the most campaign funds.

At first, Obama joined with Harry M. Reid (D-Nev.), then the Senate majority leader, and other leading Democrats to block Burris's appointment. Burris refused to give up, holding news conferences outside the Capitol and traveling to Springfield, Ill., to plead his case to leading state Democrats.

After several days, and a ruling from the state Supreme Court, Reid gave in and allowed Burris to take his seat in the Senate.

Here's an example from the following year: After then-Sen. Arlen Specter switched parties, Obama, Vice President Biden, Reid and others tried to clear a path for him in the Democratic primary. But Joe Sestak refused and defeated Specter later that spring.

It was very different just four years earlier. Then during the 2006 midterm elections, Senate Democrats successfully shoved aside a liberal firebrand in Ohio in favor of Sherrod Brown, an experienced House member at the time who went on to easily win that Senate race.

"It used to be impossible to work outside the party," said Holmes, whose first campaign was working on the Cheney-mandated Coleman race for the Senate.

The Moore case is obviously different, given the nature of allegations against him, so it probably more closely resembles the Republican establishment's inability to try to force Todd Akin to relinquish his Senate nomination in August 2012.

In a local TV interview, Akin had suggested that a woman could not get pregnant during a "legitimate rape" to explain his antiabortion views in all circumstances. It was factually wrong and politically fatal, driving female voters away from Akin in what should have been an easy win for Republicans against Sen. Claire McCaskill (D-Mo.) in a year that a GOP presidential nominee won the state by 10 percentage points.

McConnell rallied the opposition to Akin, including Mitt Romney, but the congressman refused to yield. He lost to McCaskill in a landslide.

One cause of this diminished clout is the Supreme Court's 2010 Citizens United ruling, allowing for the flourishing of unlimited donations to super PACs and other dark money entities that can fund renegade campaigns outside traditional avenues.

Stephen K. Bannon, the former Trump strategist, is trying to use his Breitbart News media platform as a central hub of anti-establishment groups both to provide financial support for candidates such as Moore and to amplify their message to their supporters.

Rather than back away from Moore, Bannon has instead falsely accused The Post of working with the former judge's opponents to plant the story. He wants Alabama voters to rally around Moore as a way to offend McConnell.

Ultimately, Moore may be guided out of the race, but it will not be from any pressure applied by McConnell. More likely, it would have to come from close friends in Alabama — and would probably happen only if new polling showed a collapse in support in a race in which he previously had a clear edge.

In 2012, Akin caused a contagion effect in other Senate races. Another Republican gave a bad answer to a rape-related abortion question and lost, while other candidates in close races kept getting peppered with questions about Akin's views.

As The Post's Michael Scherer and David Weigel reported Friday, GOP advisers fear that will happen again if Moore doesn't stand down and allow a different Republican to run as a write-in instead.

"I'm prepping my candidate for what he is going to say if he is asked," said one GOP campaign manager for a top 2018 race, who spoke on the condition of anonymity to not draw attention to the race.

Moore, Holmes said, "doesn't seem to care if he takes the entire Republican Party down with him in the process."

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