The sweater vest on Capitol Hill is much like what some claim of Sen. Hillary Rodham Clinton (D-N.Y.) — it’s polarizing. You love it or you don’t. You love people who wear sweater vests or you despise them.

For Rep. Thaddeus McCotter (R-Mich.), an avid sweater-vest wearer, it’s not so much that he likes it — he’s not sure he does. It’s that, with such a low metabolism, he’s chilly and needs to keep warm.

“I have a slow, 40 resting metabolic pulse,” McCotter explained last week.

Earlier this year, the congressman tore his oblique muscle and had to go to the doctor. “My doctor thought I was dead,” McCotter deadpanned. “But I was just low [pulsed].”

Rep. Mike Simpson (R-Idaho) wouldn’t wear a sweater vest if it was the last clean item of clothing in his closet. “I don’t like them,” he says. Why not? “The same reason I don’t like bow ties.”

Rachel Cothran, of ProjectBeltway.com, is also sweater-vest wary. “They can be dorky,” she says. “They’re hard to pull off stylishly — you can easily end up looking like a grandpa.

Her advice: “Sweater vests look best on a man with a trim figure, especially if he’s going to wear it alone. They’re best under a jacket for an additional shot of color or texture. If you’re going to wear it by itself, roll up the sleeves of the button-down underneath to mess things up a bit. Otherwise, you’ll end up looking like a 7-year-old whose mother dressed you for church.”

Still, McCotter insists the sweater vest can be stylish if you are Rep. Rob Bishop (R-Utah). Indeed, Bishop wears the vest, but, like McCotter, isn’t convinced he looks good in it.

“At my size nothing looks good,” he says wryly. “So the more layers the better.”

But on the whole, he likes the sweater vest. “All sweater vests look good,” he says. “It’s different. It stands out. To be honest, I’m tired of wearing black suits and seeing them everywhere.”

“They’re coming back,” Bishop claims of the vest, noting that he has three suits that have accompanying vests.