Pat Leahy, the top Democrat on the Senate Appropriations Committee, has accused Attorney General Jeff Sessions of trying to avoid questions about his interactions with Russian officials after Sessions announced he would not testify before Appropriations on Tuesday, and would instead appear before the Senate Intelligence Committee (it's not clear whether that appearance will be public). Leahy's tweets:

"Atty Gen. Sessions provided false testimony in response to questions from me and @SenFranken about his contacts with Russian officials. Now, twice in 2 mos., AG Sessions cancels an Approps hg in which I could Q him about his false testimony and half-hearted Russia recusal. My mssg to AttyGen Sessions: Approps & Judiciary have oversight of DOJ. You need to testify before both in public. You can't run forever."

The context: Sessions said during his confirmation hearings that he had not "contact with the Russians" during the campaign. It has since emerged that he had at least two undisclosed meetings with the Russian ambassador, with James Comey reportedly telling senators in a closed briefing last week of a possible third meeting.

Why it matters: The Democrats are out for blood, and Sessions is clearly in a vulnerable position. Expect them to use leverage similarly on others caught up in the Russia probe going forward — 'if you don't take our questions, we'll tell the world you must have something to hide.'