I assume you're not including the stuff like swearing into office on the Qur'an? His youthful connections would worry me more if they were reflected in current ideology or something he particularly stood by now.
I don't mean to imply that Ellison is perfect of course, but he's also a solidly pro-working class liberal from the Rust Belt who's well spoken and focused. Perez would be fine with me as well, though I'm concerned with his connections to the Clinton wing of the party.