When Megan Argiro left her job on Sen. John McCain’s (R-Ariz.) staff to start a fashion business with her younger sister in New York, everyone thought she was crazy.

Almost six years later, as the sisters huddled around a television last week watching their dress grace the runway of NBC’s “Today” show wedding segment, the naysayers are being proven wrong.

“The fashion industry’s gain is our loss,” McCain said through a spokesman. “We always knew that she would be a success in whatever she did.”

On Wednesday, Megan and Kathlin Argiro will find out, along with every other “Today” viewer, if America voted their dress to adorn the four bridesmaids in the wedding that will take place in Rockefeller Plaza this September. It’s part of a summer long series in which “Today” picks up the tab and America votes online to determine every aspect of the chosen couple’s wedding. Voters have until noon Tuesday to select their favorite bridesmaid dress online.

But the sisters’ success has not come easy, and their start was not typical for the fashion world. Hailing from Alexandria, Va., the women have been “really close since we were really little,” 34-year-old Megan said. However, their paths sharply diverged in high school.

The 32-year-old Kathlin found her fashion calling when Megan set her up with a date for her first dance. Kathlin could not find a suitable dress, so she sketched what she wanted, her mother found her an apprenticeship and she made the dress for herself.

The younger Argiro moved to New York in 1988 after graduating high school and attended Parsons School of Design until 1992. Before teaming up with her sister, Kathlin was a designer for Carmen Marc Valvo and Arnold Scaasi.

Megan, on the other hand, developed an early interest in politics.

In high school, Megan and a friend snagged a summer gig with then-Sen. Gordon Humphrey (R-N.H.) in 1985.

“We were really enthusiastic,” Megan said of what she described as her “first introduction into politics.”

During her first of two summers in the Humphrey camp, Megan laid the groundwork for the ideological underpinning that would shape the rest of her political life.

“One of the things that bothered me the most was I saw all this waste,” she said of all the office supplies that were ordered but not used. “I thought, gosh, we could save so much money if we monitored these things more carefully.”

Guided by the desire to reduce government spending, Megan graduated from James Madison University in 1991 with a degree in economics and political science.

Fresh out of college, Megan started working for then-Sen. Steve Symms (R-Idaho), a member of the Finance Committee, as a legislative correspondent on tax and economic policy issues. She soon worked her way up to legislative assistant.

“It was pretty exciting to be a committee staffer,” she said.

After a stint off the Hill, when “the Democrats got control,” Megan worked for then-Sen. Dan Coats (R-Ind.), who is now the U.S. ambassador to Germany.

When Coats was co-sponsor of the line-item-veto bill with McCain, Megan worked closely with the man who would be her next boss.

“I was the lead staffer on that bill and that’s how I got to know John,” she said.

But Megan soon grew weary of Washington. The older sibling said she “didn’t like how difficult it was to make things happen and change things.” She also grew tired of the repetitive nature of government.

“Even though I had been involved in a lot of cool legislative efforts, I just wanted to do something that was more of my own and that I could control a little bit more,” she said.

With McCain contemplating a run for president and the rest of his staff baffled at Megan’s decision, she said “with our two pennies rubbed together I came to New York.”

Symms, currently a lobbyist with Parry, Romani, DeConcini and Symms, said Megan’s move came as no surprise to him.

“She’s suited to whatever she puts her mind to do,” he said. “If the fashion industry is where she wants to be, she’ll be successful at it.”

But, he added, “If she was on Capitol Hill she’d be running some committee staff by now.”

Megan is putting her political training to work, however, as she runs the finance and marketing portion of the jointly owned business.

“If you sell an idea you can also sell a pretty dress,” she said, adding that it’s a bit simpler on Fifth Avenue than on Capitol Hill. “They either like the color because it’s pretty or they don’t. They don’t get into all the philosophy behind it.”

Currently caught up in the “Today” show wedding whirlwind, Kathlin, who runs the design and production side of her label, said “the phone has been ringing off the hook” since their dress was on television last Wednesday.

With about 3,000 garments to produce this month, the Kathlin Argiro brand is booming.

Competing with the esteemed designers Vera Wang, Jenny Yoo and Amsale for rights to the “Today” show’s bridesmaid dresses, the Kathlin Argiro line is being hailed by the fashion elite.

Judy Gordon, the style editor for the show and founder of thetrend report.com, called the sisters’ dress “very striking.” She added that the blue and brown combination represents the latest trend in combining colors.

She selected the dress as one of the four finalists after visiting about 15 designers and viewing nearly 75 dresses.

But Gordon was a bit more tight-lipped about her personal preference.

“I actually liked them all, but I did have a favorite,” she said in an interview. “The only hint I’ll give you is that my taste is very classic, personally.”