On Tuesday, Conservative radio host Hugh Hewitt told Yahoo! News’ Katie Couric that President Trump needs to be careful, because he’s on “constitutional thin ice.”

Trump backers have been quick to label Hewitt, who is also a law professor, a RINO, but Hewitt so far has not suggested that Trump has violated the law. Politico reports on what Hewitt said regarding the emolument clause, a constitutional provision preventing members of government from accepting gifts from foreign governments, of which some on the left think Trump is in violation.

In part, the report said the following:

Hewitt…said his interpretation of the emoluments clause stipulates that “you can’t be paid a salary by a foreign government for an office, not an arms-length transaction.” He added that his former boss, Fred Fielding, White House counsel for Presidents Ronald Reagan and George W. Bush, helped Trump’s incoming White House counsel, Don McGahn, during the transition.

“And they came to the conclusion that clause does not apply to arms-length transactions with hotels,” Hewitt said.

Though Hewitt believes that Trump is not in violation of the Constitution here, he warns that should he continue to act in ways of questionable constitutionality, he could find himself in danger of impeachment.

“[A] Democratic congressman introduced an article of impeachment already. So if President Trump gets wiped out in 2018 … and if, in fact, Democrats get a majority, Republicans will not throw themselves in front of a train to stop it. So President Trump has to be aware of the constitutional thin ice on which he skates.”

Trump, as well as the Republicans in Congress, are not in a position to appeal to the goodwill of the American people either. A solid majority are already wary of the Trump administration. As reported by Roll Call, a recent Economist/YouGov poll, for example, finds over 60 percent believe there will be major scandals during his presidency and almost 40 percent believe that there will be numerous major scandals.

Trump needs to tiptoe to keep from falling in, which is something he has probably never done in his life. The lack of self-control he exhibits is one of many reasons his critics questioned how presidential he could actually be. Here is another opportunity to test him, but by this point, few people are on the fence on that question.

Trump is five days into his presidency and already running short on political capital, and that is Hewitt’s point.