DECATUR, Ala. — With the thunder and fire of an old-time revivalist, U.S. Senate candidate Roy Moore rose before the assembled souls at the Redemption Baptist Church, a front-runner in the polls days out from an election that could rattle the rickety structures of the Republican Party.

“You think that God’s not angry that this land is a moral slum?” asked Moore, 70, reciting a rhyming poem he had written years earlier during a 50-minute address before several dozen believers. “How much longer will it be before his judgment comes?”

Republican primary voters across the country have been trying since 2010 to elect angry, outsider candidates who promise to disrupt the ways of Washington. But no one in recent history has promised to be quite as disruptive as Moore, a former chief justice of the Alabama Supreme Court who has twice been removed from the bench for defying judicial orders.

And few have divided the Republican Party as Moore’s candidacy has, producing a momentous power struggle over a special election that is likely to turn out less than 20 percent of Alabama’s Republican voters but could nonetheless set the tone for the coming 2018 election battles.

In August, Moore won the first round of primary voting with 39 percent of the vote, and then won the endorsement of the third-place finisher weeks later. Now, with the election just five days away, Moore leads public polling averages with a nine-point edge over Sen. Luther Strange, the man appointed to replace Attorney General Jeff Sessions.

Strange, a 6-foot-9-inch former prosecutor in the conventional mold of his colleague, Sen. Richard Shelby, R-Ala., is bolstered by millions of dollars pouring into the state from establishment Republicans including Senate Majority Leader Mitch McConnell, R-Ky., by the U.S. Chamber of Commerce – and by President Trump, who flew to Huntsville on Friday to appear at a rally for Strange.

But many of Trump’s core supporters remain with Moore, who praises Trump’s policy agenda on the campaign trail. So are a hodgepodge of conservative iconoclasts: former Trump adviser Stephen Bannon, former Alaska governor Sarah Palin, “Duck Dynasty” star Phil Robertson and evangelical leaders from across the country.

And for now, they are winning, revealing with startling clarity the gaping divide between Trump’s most ardent fans and Republican leaders – and setting up, among other things, the possibility that many of them could turn out to see Trump as he tries to prop up Strange, and then vote for Moore.

The central argument of Moore’s campaign is that removing the sovereignty of a Christian God from the functions of government is an act of apostasy, an affront to the biblical savior as well as the Constitution. Among the prices he says this country has paid for denying God’s supremacy: the high murder rate in Chicago, crime on the streets of Washington, child abuse, rape and sodomy.

“We have forgotten the source of our rights,” Moore preached during that church appearance, quoting from memory several books of the Bible, along with the Declaration of Independence, Abraham Lincoln and George Washington. “We put ourselves above God. And in so doing, we forgot the basic source of our morality.”

Moore has always been controversial, and proudly so. As a judge, he denied granting custody of three teenagers to their mother, who was in a lesbian relationship, writing that her private behavior was “an inherent evil against which children must be protected.”

In his current campaign, he has called for the impeachment of judges, including possibly Supreme Court justices, who issue rulings for same-sex marriage and sodomy.

In 2003, when a federal judge ordered Moore to remove a monument to the Ten Commandments he had installed at the Supreme Court of Alabama, he refused. He could not, as an officer sworn to the Constitution, carry out an illegal command, he explained. He was removed from office.