This question is for lawfags: it's been bugging me for a while that these Dems in Congress are able, without legal repercussions, to violate the rights of citizens by issuing subpoenas and starting investigations without evidence of a crime. What legal mechanisms exist to punish such malpractice? How could (are) those mechanisms being circumvented or cheated? We've got Sandmann starting the wave of suing for defamation, which is a good check on media, but what can check these government officials? I'd really like to understand the legal boundaries and penalties–do they exist?