Donald Trump says collusion is not a crime. That's not right.

President Donald Trump has consistently denied that any collusion took place between his campaign and Russia. Now, Trump and lawyer Rudy Giuliani are putting new emphasis on the question of whether collusion itself is a crime in the first place.

"Collusion is not a crime, but that doesn’t matter because there was No Collusion (except by Crooked Hillary and the Democrats)," Trump tweeted July 31.

Giuliani made the same point a day before, telling CNN, "I don't even know if that's a crime, colluding about Russians."

This isn’t the first time Trump has dismissed collusion on legal grounds. In a December interview with the New York Times, he noted the views of Harvard emeritus law professor Alan Dershowitz.

"I watched Alan Dershowitz the other day," Trump said. "He said, No. 1, there is no collusion, No. 2, collusion is not a crime."

For this fact-check, we’ll sort out how collusion overlaps with the law.

• The press uses the term collusion to describe a range of activities that might have taken place involving the Trump campaign and Russian representatives.
• Collusion is part of antitrust law (but those statutes are irrelevant in this situation).
• While the special counsel investigation has produced indictments and guilty pleas, it’s too early to say whether the Trump campaign broke any laws.
• Legal opinions vary, but people who know the law say that certain statutes could have been violated.
• The common use of the word collusion includes potentially illegal behavior.

If Trump were talking about the purely legal use of the word collusion, he would be wrong. Collusion falls under federal antitrust law, and it involves competing companies that cut secret deals to boost each other’s profits.

Trump isn’t using the word that way, and nor is anyone else. The issue is whether people in the Trump campaign knowingly boosted Russian efforts to undermine Democratic candidate Hillary Clinton to the benefit of candidate Trump.

Russia’s intentions are not disputed, at least not among U.S. intelligence agencies and special counsel Robert Mueller’s investigation.

The focus is on what the Trump campaign did and whether that was illegal, regardless whether the relevant statute contains the word "collusion."

Harvard legal scholar Dershowitz found it hard to see what law the Trump campaign might have broken, even if it knew in advance about emails that Russian operatives allegedly stole from the Democratic National Committee and Clinton’s campaign chair John Podesta.

"Obviously, if anyone conspired in advance with another to commit a crime, such as hacking the Democratic National Committee, that would be criminal," Dershowitz wrote in 2017. "But merely seeking to obtain the work product of a prior hack would be no more criminal than a newspaper publishing the work products of thefts such as the Pentagon Papers and the material stolen by Edward Snowden and Chelsea Manning."

Defense attorney William Jeffress told Politico that "collusion with the Russians in attempting to affect the outcome of the presidential election is a serious political scandal, but I must say it is not clear that it provides a basis for criminal prosecution."