Granted, Alabama Republicans twice rejected Mr. Moore, overwhelmingly, when he ran for governor. But the first time, in 2006, was when unattractive details of his messy first eviction from office were still fresh — details such as his personal copyright notice on the 5,280-pound Ten Commandments monument he erected at the state high court. That campaign also took place against a popular Republican incumbent whom voters wanted to retain.

In his second try for governor, in 2010, Mr. Moore seemed an underfunded has-been, already rejected for the office — and perhaps not deemed to have an executive skill-set. Just two years later, though, what remained in the public mind was the image of the lonely martyr, fighting for God’s justice. So, in an upset against two respected and well-funded primary opponents, running for his familiar old court seat rather than to lead the whole state government, Mr. Moore won that 2012 primary without even needing a runoff — and then defeated a spirited Democrat in the general election.

What Mr. Moore proved then was that his grass-roots organization, through evangelical churches and through new forms of social media, could turn out voters in a way traditional politicians couldn’t. In any low-turnout special election, especially, his enthusiastic base of supporters would provide him an asset no money could buy.

(To my chagrin, I saw that organization in action. Mr. Moore campaigned quite specifically against me when I temporarily left journalism to run in a special election for Congress in 2013; his candidate performed twice as well on Primary Day as polling had indicated, thus qualifying for the runoff, while leaving me in fourth place among nine entrants.)

Thus, running to represent Alabama’s angst against Washington, as an advocate in a 100-person Senate rather than a chief executive, Mr. Moore was always a strong bet at least to make the primary runoff. When Mr. McConnell’s PAC began running misleading ads against Mr. Moore’s personal finances, it only enhanced the judge’s reputation as anti-establishment hero.

What some didn’t expect was that Mr. Moore would run first, rather than second, against the well-funded Mr. Strange, especially after Mr. Trump went “all in” for Mr. Strange with tweets and robocalls. That Mr. Moore ran a full six percentage points ahead of Strange (39-33) shows that not even this Trump-loving state Republican base admires the president more than it admires its “Ten Commandments” folk hero.

Despite renewed efforts by Mr. Trump and Mr. McConnell, Mr. Moore’s prospects in the September runoff look good: He likely will inherit most of the 20 percent who supported hard-line conservative, third-place finisher Mo Brooks — who was relentlessly attacked by Mr. Strange’s ads and who in turn strongly blasted Mr. Strange during his concession speech.

In this overwhelmingly Republican state, Mr. Moore is the betting favorite to become the newest United States senator. For the political tough-guy reputations of Mr. McConnell and Mr. Trump, the blow would be monumental.