I think Donald Trump causes problems for himself the same way a guy who's functioning as his own lawyer: he's going to end up doing something that might be benignly motivated, but in practice is illegal. For instance: why does the executive in command of the best spy and policing organizations in the world have to issue public calls for foreign governments to investigate his political rivals? Just use the CIA like Lyndon Johnson, or use the IRS like Barack Obama. I can see Trump answering innocently, "It's not collusion if you do it in a press conference." I'm pretty sure that's not correct.
I find it interesting, though, that this opinion piece in the Washington Post frets, "If we legitimize foreign governments investigating our politicians, no politician will be safe to have freaky sex on overseas visits!" Welcome to the panopticon, moron. I believe the proper response is, "If you have something that you don't want anyone to know, maybe you shouldn't be doing it in the first place."