so who'd be the "middlemost" pol in the US right now? who do moderates have?

AFAIK? Nobody. Neither side seems to have any interest (or, more likely, sees any advantage) in presenting a viable candidate that isn't as partisan as possible. Probably because doing so would require them to give ground on one or more core party stances, without the guarantee of a meaningful return that would make up for whatever they lose from the party faithful.

And, having shown that they'll loosen up on these issues enough to try and catch the moderate voters at election time, they'll be faced with the inevitable calls of "well, you were willing then, why not now" when those issues are raised at another time.

Also, and this just occurred to me, but a candidate who can bring in the moderates in numbers enough to matter might become a threat to whatever party they're from (or both, if it's a bonafide independent), forcing them to go down roads that they don't want to step foot on.