Mr. Trump, a profane, bombastic, thrice-married New Yorker, may not have been the candidate many religious conservatives prayed would win the White House. But the mutually beneficial arrangement he has nurtured with the Christian right is already starting to nudge the government in a more conservative direction.

The religious right’s influence is evident in the policies the new administration has prioritized in its first weeks, from Mr. Trump’s clampdown on federal funding that could indirectly support abortion to his directive to give persecuted Christians special dispensation to enter the United States. His pick to fill the vacancy on the Supreme Court, Judge Neil M. Gorsuch, has written opinions favorable to businesses that have religious objections to government mandates. And the White House has told leaders of the movement that the president will select nominees for the lower courts who are opposed to expanding abortion rights.

A group that has felt shunted aside by the Republican establishment is finding doors open more quickly and willingly than it did even under friendly presidents like Ronald Reagan and George W. Bush.

Mr. Trump has given many conservative Christian leaders his personal cellphone number. He has solicited their advice for filling key positions. He has invited them to the White House. And he has staffed his cabinet with many people of deep Christian faith, like Ben Carson, a Seventh-day Adventist, and Betsy DeVos, who was raised in the Calvinist tradition.

Now that he has the movement’s support, he has good reason to keep its adherents happy. He needs them to preserve his cobbled-together base of voters. And given how few votes put him over the top in the Electoral College — 77,000 total in Michigan, Pennsylvania and Wisconsin, where socially conservative Republicans are a key constituency — he may indeed owe them the election.