People meet with Congress members all the time, trying to make them change their minds. Hasn't happened yet to make Democrats vote in favor of Trump.

Unless you're thinking along the lines of the military threatening to send them to Gitmo for not voting how they want them to, in which case that violates the hell out of the Constitution and represents a very seious type of voter fraud. Both of which we're supposed to be vehemently opposed to. So I'm hoping that isn't what you're thinking.