I've been thinking about this quite a bit as the pressure on Trump picks up. I think part of the difficulty in holding Trump to task over his screw ups (and possibly crimes) is we have been told for 20 years that these same screw ups (and possible crimes) are not a big deal. The last two democratic presidents had campaign violations much bigger than Trumps supposed violation and there was hardly a peep or any outrage about it. Clinton an other politicians have paid off former lovers to keep them quiet (sometimes even rape accusations have been covered up with hush money). Obama and the Clintons have had nefarious ties to foreign governments that were questionable at best and criminal at worst.
These are all things that should be a big deal and should be enough for us to not vote for these guys. It's part of the reason I didn't vote for Trump and the reason I didn't vote for Vitter in the last governors race. The real issue is that only one side seems to be held accountable by the press and the DOJ/FBI/etc. With the MeToo movement I think an argument could be made that Clinton wouldn't have gotten away with his indiscretions in this day and age, but some of the other items are much more recent and hard to argue that there has been a sudden shift in thinking that everyone going forward is going to be held to the same standard. I see no evidence of that. That makes it hard to muster a lot of outrage that seems to be limited to the people who want him gone anyway.