With ten days until the Iowa Caucus, the gloves are coming off for candidates on both sides of the aisle.
It's the last chance to score political points, and that means poking at tax plans, talking about tough military strategies, and … impressing voters with your masculinity?
Republican candidate Marco Rubio recently got hammered by fellow conservatives, after rocking a pair of high-heeled men's boots.
Weeks later, the New York Times reports that Rubio has changed his stump speech to highlight his more hawkish policies.
He made a photo op out of buying a gun. He even talks football in a new campaign ad.
How important is masculinity in convincing voters you've got the presidential vibe?
Cal State Fullerton American studies professor John Ibson says it matters a lot more to a certain type of voter.
American Masculinity, a history
Ibson says masculinity became part of the political discourse at the end of the 19th century. That's because America was rapidly evolving.
"The nature of American life had changed. We were becoming much of an indoor society. Industrialization was fully taking effect, and so there was this feeling that American men were losing their strength," Ibson says.
Ibson says sexual orientation also became a topic of discussion for the first time.
"While people have been having sex with members of their own sex for as long as there have been people, the equation of homosexual males with weakness was a way to further stigmatize weakness and also stigmatize gay men," Ibson says.
Who really cares?
Turning again to "Bootgate," Ibson says traditional concepts of masculinity only really matter to conservative voters, making Rubio's boots an effective way to chip away at his popularity.
"It really is -- today -- only in right-wing Republican circles that such juvenile concerns would get any traction," Ibson says. "That's really where homophobia and sexism still thrive ... It's hard to imagine in any Democratic political circles, where there were high-heeled boots on some candidate, being a stick to beat him with."
Ibson points to the GOP debates for an example.
"It is a [kind of] arm wrestling contest in their debates to show who's the toughest," Ibson says.
He adds that Democrats aren't perfect either but in regards to masculinity, the issue was settled a long time ago.
"JFK ... there was a great deal of sexism in his attitude toward women. It was a different world then, and I think the Democratic Party has adapted itself much more successfully to that cultural world than -- at least -- large segments of the Republican Party have," Ibson says.
Hillary Clinton and Carly Fiorina
Ibson says there may be extra pressure on Hillary Clinton to appear tough, but based on her foreign policies, there may not be much to prove.
"In fact, one might object to some of Hillary Clinton's foreign policy for being a little too aggressive and tough," he says.
Ibson adds the same may be true of former HP CEO and Republican candidate Carly Fiorina.
"She does seem to emphasize her toughness and her aggressiveness, but I think that's less her being a female ... that may be just the kind of person she is."
Press the blue play button above to hear the interview.