Eh, if there's zero chance of either party preventing the other from getting things through you run into issues.
You do run into issues but it also solves some stuff. If Nancy Pelosi is Speaker, a Democrat is Senate President and Clinton is President President then congress is going to be passing budgets no if and or buts. If republicans try to filibuster all budgets then democrats are going to change Senate rules to curtail use of the filibuster. That is just a bridge too far...
context versus content
I would vote for Alvin Greene. I think that Alvin Greene type candidates would never win in a competitive election unless republicans put up someone like Trump.
If the republicans had ever run a good candidate against someone like Marion Barry or Rob Blagoyovoylitchavich, I would vote for said republican. But said republican would need to represent a constituency to their left, which means accepting a candidate I doubt they would ever accept. I think republicans could be competitive even in democratic lock places like DC if they weren't so rigid.
Basically if all else is equal, I would vote for the party label and nothing else. I've done that many times with less noteworthy candidates (I live in a conservative district so I vote for a sacrificial democratic lamb every year). But often the character of a person is deeply informative about why they would be terrible at the job (such as Marion Barry).
I guess Obama is a useful idiot for trying diplomacy with Iran and Cuba then, Mainiac? If she was belligerent about Russia, you'd probably hate that, too. Let me guess, if someone is either slightly more friendly, or slightly less friendly to Russia than Hillary is, then they're automatically an idiot?
There is a difference between diplomacy and a photo-op for dictators who want to prop you up so in order to peel off a few votes from the candidate they want to lose.
And yes, sometimes diplomacy does mean you give a photo-op to dictators. Quid pro quo. But Jill Stein isn't doing diplomacy here. She is just posing with a man who is the opposite of everything she claims to stand for.