It's called Impeachment.
I have no idea what grounds they'd use, but I'm sure they can think of something.
I don't think they can. All this complaining is just for the cameras and people who don't read decisions. Whittemore in his decision cited Senate transcripts showing without a doubt that the Senate did not intend to influence the judge's decisions in any way, leaving his discretion in issuing an injunction purely up to current law.