Sophia Bush is very outspoken when it comes to the Presidential election -- and in an exclusive interview, the "Partners" star tells toofab why she's ticked with Mitt Romney.

toofab's Anna Kachikyan talked politics with the "One Tree Hill" stunner at Wednesday night's 3rd Annual Autumn Party benefiting the Children's Institute hosted by PSLA ... and she didn't hold back.

The 30-year-old actress has some big problems with the GOP candidate, namely when it comes to his economic plan and stance on women.

"I'm pissed off that he thinks my uterus is any of his business," Sophia tells toofab. "Give me a break, it's not the 1950s Mr. Romney. And if you'd like it to be, the women of America are going to have some opinions for you."

Her stance comes after the debate this week, where Romney said he was flexible on his female chief of staff so she could be home by 5pm every night to make dinner for her family ... and also bizarrely boasted about "binders full of women."

It's clear Bush is voting Obama.

"I'm really looking forward to seeing him get reelected and I'm looking forward to remaining a proud American citizen," she says.

Of course, not everyone's going to agree with Sophia ... nor do they have to. Check out the video above to see how she deals with Twitter followers who don't necessarily agree with her political tweets.