Clinton was impeached. It's the equivalent of an indictment. The case was argued in the Senate, a vote was taken and it was insufficient for 'conviction' and removal from office.

Clinton lost his law license. GOP lost its argument to the public because everybody knew someone who lied to their wife or to their husband about an affair. And because it was private consensual sex.

If Trump's tax returns are released they may reveal financial entanglements that place him in violation of the Emoluments Clause.

And if he is implicated in the Russian efforts to influence the election in his favor, of course there will be cries for his impeachment.