And it is here in Iowa, where conservatives traditionally have an inordinate influence in the state’s Republican presidential caucuses, that evangelicals have their best shot of shaping the field. In what he says is his effort to restore “our Christian heritage,” Mr. Lane’s American Renewal Project has already shown its influence in Iowa by helping to unseat three State Supreme Court justices who voted to allow same-sex marriage.

But Mr. Lane’s ambitions are national — he focused on battleground states in 2014 and has built an email list of 100,000 pastors around the country.

His goal now is to get 1,000 pastors to run for public office, and their potential support has drawn a virtual pilgrimage of conservative candidates eager to join the tours Mr. Lane organizes to Israel and to his “Pastors and Pews” events.

“A good friend” Mr. Cruz said.

“A great friend,” Mr. Jindal said.

With some of the energy gone from the evangelical movement, said John C. Green, a political scientist at the University of Akron and an expert on evangelicals, “this is about keeping the pressure on for the next election.”

“Lane has influence with pastors, and they listen to him,” Mr. Green added.

All this activity has caught the attention of liberal opponents, who call Mr. Lane an extremist for his belief that abortion will incur divine vengeance on America and his argument that the Republican Party will be destroyed by its acceptance of same-sex marriage just as the Whig Party was destroyed by its acceptance of slavery in the 19th century.

They have sought to cast him as the de facto travel agent for the American Family Association, a Mississippi-based conservative religious organization, which had to distance itself from a spokesman, Bryan Fischer, who called homosexuals “Nazis” and argued that Muslims should not enjoy First Amendment rights and should be converted to Christianity.