People who remember the old comic strip "Peanuts" will recall an often repeated situation where Lucy offers to hold a football for Charlie Brown to kick. Then, as Charlie coming running up to kick it, Lucy snatches away the ball and Charlie Brown loses his balance and goes crashing on his backside.
The reason this same scene remained funny, despite how often it was repeated, is that in the later repetitions Charlie Brown would express suspicion at Lucy, recalling how she had tricked him before. She would then come up with some claim that she wasn't going to do that any more-- and of course she did.
There is a similar routine that has been repeated many times in Washington, over the years, with the Democrats playing Lucy and Republicans playing Charlie Brown.