Probably several times each but that's not the big scandal is it?
"Are these meetings generally controversial or not?
They are generally not controversial, experts agreed.
"It is fair to say most of these contacts are not problematic," said Benjamin H. Friedman, a research fellow in security studies at the libertarian Cato Institute.
Here?s a big reason why: The United States has a separation of powers between the executive branch and the legislative branch, and because of this, members of Congress have the right -- and the obligation -- to gather their own information before making decisions, rather than just rely on information from the executive branch.
"It is the nature of our system that each senator can have their own little foreign policy and talk to diplomats," Friedman said. "They are not compelled to follow the White House?s lead."
Christopher Madison, a former aide with the House Foreign Affairs Committee and the Senate Foreign Relations Committee, agreed.
"Meetings are what D.C. is all about," Madison said. "Certain countries may be radioactive, but most are not. Russia was not previously."
Ted Bromund, a senior fellow at the conservative Heritage Foundation, said there?s nothing "untoward" about such meetings.
"In many cases, these are basically lobbying visits ? which after all is what foreign diplomats are here to do," Bromund said. "And so what? Some things foreigners want are in our interests, others are not. How is one to decide without meeting them?"
Both McCaskill and Sessions "were doing their job," Bromund said."
Four questions about when senators meet with ambassadors | PolitiFact