So when a spokeswoman for Sessions, the former Alabama senator, suggested in a statement Wednesday night that his contacts with the Russian ambassador were a function of his duties as a member of the committee, McCaskill weighed in with a tweet.
"I've been on the Armed Services (Committee) for 10 years," the Democrat said. "No call or meeting w/ Russian ambassador. Ever. Ambassadors call members of (Foreign Relations Committee)."
But as National Review editor Charles C. W. Cooke quickly noted on Twitter
, McCaskill's social media feed includes some mixed messages.
In January 2013, she tweeted, "Off to meeting w/ Russian Ambassador. Upset about the arbitrary/cruel decision to end all US adoptions,even those in process."
More than two years later, in August 2015, she again posted plans to chat with foreign ambassadors, including the one from Moscow.
"Today calls with British, Russian, and German Ambassadors re: Iran deal," she wrote.
McCaskill on Thursday acknowledged having spoken to the Russian ambassador as part of discussions about the Iran nuclear deal and blamed Twitter's character limit for confusing her point.
"One-hundred and forty characters are tough. The word 'from' should have been in there but I didn't have room," she said.
But McCaskill, who is calling for Sessions to resign, doubled down on her assertion that Sessions' personal meeting with the Russian ambassador was unusual for a member of the Armed Services Committee.
She also suggested that Sessions, a former US attorney, intentionally misled Congress and would, by his own standard, face still stricter consequences. She also drew a distinction between her interactions with the Russian ambassador and Sessions'.
"You do not forget a one-on-one meeting in your office with a Russian ambassador," McCaskill said. "If (Sessions) were the prosecutor, he would go after somebody" who provided a similarly misleading statement.