“There are conservatives here who maybe read into Russia things they wish were true in the United States,” said Angela Stent, director of the Center for Eurasian, Russian and East European Studies at Georgetown University. “And they imagine Russia and Putin as the kind of strong, traditional conservative leader whom they wish they had in the United States.” To these conservatives, she added, “Russia is the true defender of Christian values. We are decadent.”

Mr. Trump’s opponents have tried repeatedly to make an issue of the mutual admiration between him and the Russian president, anticipating that Republicans would not tolerate any whiff of sympathy from one of their own toward the leader of what Ronald Reagan called the “evil empire.” But Mr. Trump has never had to wait long for conservatives to leap to his defense — and often Mr. Putin’s as well.

“My guess is that Trump voters would say: ‘Hey, you know what? I kind of like the fact that Putin’s endorsed Trump,’ ” Rush Limbaugh told his listeners in December 2015. “At least Putin’s killing terrorists. At least Putin’s made an enemy out of ISIS. We don’t seem to be able to do that.”

After Mr. Trump was elected and evidence of Russian hacking had started to accumulate, the praise for Mr. Putin from the right continued. Kimberly Guilfoyle, a Fox News host who once said Mr. Trump had considered naming her as his press secretary, said that she wished Mr. Putin could be president of the United States for just 48 hours. That way, as she put it, “Americans don’t have to worry and wake up in the morning fearful of a group that’s murderous and horrific like ISIS.”