His comments on Russia have drawn ire and befuddlement from his Democratic political foes, but on this issue more than most, he seems to have fewer conservatives who share his outlook.
Republicans scatter when Trump talks Russia. Some prominent conservatives wouldn't even agree to be interviewed by ABC News for this story.
Trump said today he was being "sarcastic."
Maybe so, but it's not the only statement of that ilk.
Danielle Pletka, a foreign policy and defense expert at the conservative think tank American Enterprise Institute in Washington, D.C., said the Republican establishment has rightfully been hard on Trump.
"Does anybody who believes in democracy, does anybody who believes in the system that’s been in place since the end of World War II think that it's permissible to bite off and annex another part of a country? No. Nobody serious thinks that," Pletka told ABC News.
White House spokesman Josh Earnest described today the annexation of Crimea as an "egregious violation of international norms" that rallied Europe and the U.S. to impose sanctions against Russia.
Trump has suggested the U.S. step back from the unrest in Ukraine.
"I think maybe we should do a little following and let the neighbors take a little bit more of an active role in Ukraine," Trump said in a television interview late last year.
“If they fulfill their obligations to us, the answer is yes," Trump told The New York Times when asked if he would defend the Baltic states from an attack by Russia. NATO members are required to spend 2 percent of their GDP on national defense.
"What Trump fails to understand, because he thinks so transactionally," Pletka told ABC News, "is that we are in NATO not because of the 2 percent that the likes of Latvia throw in or not throw in. We are in NATO because it is the most secure, most successful alliance in modern history. And it is our interest to be in NATO. I can assure that an extra million dollars in the defense budget of Greece is not going to transform the landscape."
"He's running his country and at least he's a leader, unlike what he have in this country," Trump said. And when Putin described Trump as a "bright and talented person," Trump released a statement through his spokesman, Hope Hicks, that said in part: "It is always so great to be so nicely complimented by a man so highly respected within his own country and beyond."
Pletka said Trump's foreign policy statements might be playing into Putin's hands.
"I think it's absolutely clear that Putin would love to see someone like Donald Trump, who shares his antipathy towards civil society and democratic norms, elected," Pletka said.