Sen. Ron Johnson is as clean-cut as they come — a button-down Midwesterner with nary a hint of hair on his face.

His staff, well, that’s another story, at least this month.

Four members of the Wisconsin Republican’s staff had an extra daily task to focus on in November: grooming their mustaches for a good cause.

“It’s motivated by a desire to do what they can to raise money to fight prostate cancer,” Press Secretary Brian Faughnan said.

Johnson’s office is participating in “Movember,” an annual November event to raise awareness and money for certain cancers that affect men.

Not to be confused with “No Shave November,” Movember specifically encourages participants to grow mustaches for charity.

Like other Movember participants, Johnson’s staffers have created a team, the Rollies Fingers, and a page on Movember.com to help encourage donations. The team is named after baseball Hall of Fame pitcher Rollie Fingers, a former Milwaukee Brewer who is famous for his handlebar mustache.

“Movember is all about creating a men’s health movement and creating a world where men live aware of their lifestyle,” said Jack Choate, a former Hill staffer and aide for the National Republican Senatorial Committee who is now director of development for Movember U.S.

This year, some Hill staffers participated in the inaugural Capitol Hill Movember Challenge, which was more of a trial run to gauge interest of staffers. The teams included the Senate Staches and House Handlebars.

Tommy Holstien, a staffer for Sen. Kay Bailey Hutchison (R-Texas), reached out to Movember to help develop the challenge on the Hill.

“It’s a neat event for us on the Hill because we are around so many different types of people that come on a daily basis,” Holstein said. “It’s access that we have to create awareness.”

He added that he hopes the Hill challenge can attract more participants and — who knows — maybe even a Member one day.

No major-party presidential nominee has sported facial hair since Republican Thomas E. Dewey (who lost twice, in 1944 and 1948, which might explain why none has since). It has been almost a century since President William Howard Taft groomed his mustache in the White House.

But legislative branchers have continued to don beards, mustaches and even day-old scruff. And when lawmakers vote to stop shaving, people take notice.

Rep. Darrell Issa (R-Calif.) received some press last month when he wore a Nixonian five o’clock shadow during floor votes. It didn’t last. He appeared clean-shaven the next day. Last year, Sen. Tom Coburn (R-Okla.) faced a flurry of media attention when he grew out a beard at the end of the 111th Congress.

At last count, there were more than two dozen House Members and a single Senator — freshman Republican John Hoeven of North Dakota — sporting facial hair as a regular thing. According to the American Mustache Institute’s online style guide, most of the mustachioed lawmakers on the Hill are sporting the “painter’s brush,” or a “thick mustache covering the width of the mouth, usually worn short, with slightly rounded corners.”

Facial hair has recently become a popular topic beyond the world of Congressional politics.

The American Mustache Institute earlier this month rescinded its endorsement of GOP presidential candidate Herman Cain, according to its website. And former state legislator, Democrat and mustache-wearer John Gregg (a hybrid “chevron-walrus” look), is running for governor in Indiana using a mustache logo on his campaign sign and website.

Although some Members have made facial hair an accepted style choice in D.C., the clean-cut nature of Capitol Hill still makes growing mustaches something of a challenge.

“They’re definitely hearing a little bit of teasing [on the Hill] as their facial hair grows in,” Faughnan said of his fellow staffers. “But they’re probably hearing more from unhappy spouses and girlfriends.”

Choate noted that although sporting a mustache can sometimes elicit jokes and jabs, it also helps promote discussions about Movember.

“You go into a meeting and start it off with ‘Hey my name is Jack, I’m growing a mustache for Movember. Have you heard of it?,’” Choate said. “They end up asking you questions and forget about what the meeting was going to be about in the first place.”