WASHINGTON >> Between the chilly temperatures and the pace of the push-ups, there was plenty to complain about after eight lawmakers straggled into the park behind the Longworth House Office Building for their regular 6:30 a.m. workout.

While the others in the group griped and groaned on a recent Tuesday, Rep. Tulsi Gabbard, 34, her Hindu prayer beads wrapped around a wrist for her daily yoga meditation, said little.

“Tulsi, you hearing a lot of whining?” asked Rep. Markwayne Mullin, R-Okla., a former professional mixed martial arts fighter who leads the workouts, mocking the complaints of her companions.

“I’m feeling like whining,” she replied between push-ups.

Gabbard, D-Hawaii, has a reputation among her colleagues for being a composed, contemplative presence in a chamber more prone to reaction than reflection. But lately she has started to shed that persona. Since the deadly attacks in Paris, she has become a high-profile critic of President Barack Obama’s policies in Syria by amplifying her argument that President Bashar Assad should stay in power to avoid elevating the Islamic State and by introducing legislation to defund U.S. efforts to overthrow him.

Shortly after voting with House Republicans this month to drastically tighten screening procedures for Syrian refugees — in defiance of Obama’s veto threat — Gabbard traveled to Paris. From there, she made the case for focusing on defeating the Islamic State in her fourth national television interview of the week.

“My responsibility is to the people of Hawaii and the American people to stand up and fight for what is right and what is in the best interest of our country,” she said in an interview Tuesday. “That has nothing to do with party politics.”

It is not exactly what Democrats had envisioned when they tapped her for stardom.

That unexpected burst came just weeks after she bucked the chairwoman of the Democratic National Committee, Rep. Debbie Wasserman Schultz of Florida, by calling for more presidential candidate debates.

Those fights have left Gabbard straddling the line between being a next-generation leader for Democrats and a prominent critic of her party’s leaders.

“You couldn’t get a better role model,” said Rep. Steve Israel, who led the Democratic Congressional Campaign Committee when Gabbard was first elected in 2012. “She reflected the diversity of the caucus and at the same time had amazing credibility on the issue of national security.”

Gabbard, who served two combat tours in the Middle East and holds the rank of major in the Hawaii Army National Guard, has also called for the U.S. to suspend its visa waiver program with European countries until the intelligence community can catch up with the influx of Syrian refugees, an economically risky proposition.

“You want to talk about the effect on the economy if these actions are not taken and an attack is allowed to occur here, even though we’ve identified this vulnerability?” she said on CNN this month.

While Gabbard is only now becoming better known in Washington, her résumé has long attracted attention. At 21, she became the youngest person ever elected to the Hawaii Legislature. A year later, she joined the National Guard. The year after that, she abandoned her re-election campaign to voluntarily deploy with the rest of her unit to Iraq — a decision she recounted when the party showcased her with a brief speech at the Democratic National Convention in 2012 as a candidate for Congress.

When she was sworn into office in 2013, she became not only the first Hindu and the first American Samoan elected to Congress, but also one of the first female combat veterans. So it is no surprise that leaders in both parties have kept an eye on Gabbard, a risk-taker who loves to surf and ordered her wedding dress five days before her ceremony in April.

“That leadership, no disrespect, is a much older generation, and there’s this younger, new generation that’s coming in within the Democratic Party,” said Rep. Kevin McCarthy, R-Calif., the majority leader and one of Gabbard’s frequent workout partners. “I think she has an opportunity to be a great leader.”

The home-schooled daughter of a state senator and a former member of the State Board of Education, Gabbard has credited her parents for her early interest in public service. She helped her father, Mike Gabbard, start a nonprofit devoted to environmental education when she was a teenager, an effort that prompted her to consider a path in politics.

But glad-handing did not come naturally to Gabbard.

“I was probably not your prototype political candidate,” she said. “I had no background, no training, extremely shy, a total introvert, and really what I had was that motivation, that desire.”

She developed a knack for it, eking out an upset victory 10 years later in a hard-fought congressional primary in her Democratic-leaning district. Gabbard entered the race as a Honolulu councilwoman with a fraction of the support of an established former mayor of Honolulu, Mufi Hannemann — and walked out with 55 percent of the vote to Hannemann’s nearly 34 percent and, eventually, the seat.

Party leaders rushed to put her to work mentoring candidates about campaign mechanics and defense issues.

Shortly after she joined Congress, Patrick Gaspard, a former White House official who was then executive director of the Democratic National Committee, tapped Gabbard to become a vice chairwoman, she said, a post with fundraising, campaigning and other party duties she had to have explained to her.

“Coming to be a vice chair of the DNC is not something I ever sought out. It’s not something I knew a lot about,” she said. “I said, ‘What exactly do you want me to do?’”

It was in that capacity that she criticized Wasserman Schultz, the top officer, last month for leaving her and other party officials out of the discussions about the Democratic presidential debates — specifically, the number and the fact that candidates who participated in unsanctioned debates would be disqualified from appearing in others. Wasserman Schultz declined to be interviewed for this article.

Gabbard said in an interview that she had spoken out on principle. But to some, exposing internal disputes is a grave offense. Some Democrats privately questioned whether Gabbard — who takes pride in her independence — was well suited to the more partisan post, said one House Democrat, who asked not to be identified because the discussions were internal party matters.

Though Gabbard has been unsparing in her criticism of some of Obama’s national security decisions, some Democrats said that only made her voice more valuable.

“We Democrats on the House Armed Services Committee are not there to rubber-stamp administration policy,” said Rep. Adam Smith of Washington, the committee’s top Democrat. “We’re there to say what we think is right, and Tulsi does that and does it very well.”

Gabbard said, “I’d be dishonoring the memory of a lot of folks who I’ve served with who didn’t make it home if I didn’t stand up for what I believe is right and stand up and speak the truth.”

It is a quality that has earned her the respect of many Democrats and some Republicans. Thirteen lawmakers attended her wedding in Hawaii, including McCarthy and about a half-dozen other Republicans, said Rep. Kyrsten Sinema, D-Ariz.

Mullin, who was also on her guest list, said Gabbard “has the ability to forge relationships on both sides.”

“And she has a personality people just seem to want to work with,” he said.

Sinema, 39, said there was an emerging divide in Congress between younger members and older members. She said Gabbard exemplified a less partisan method of coalition-building that will ultimately prove more appealing to voters.

“She’s a solid Democrat,” Sinema said. “But she’s really practical in terms of how she approaches issues and gets things done.”

Sgt. Ryan Soon, 31, who served under Gabbard in Kuwait on her second tour and has been a strong supporter of her political career, said she had earned the respect of her soldiers by exhibiting a reasoned practicality, recognizing her unit’s strengths but also bolstering its weaknesses.

And her presence at ad hoc barbecues supplemented with canned goods and meals ready to eat did not hurt, either, he said.

“She was a leader that people followed not because they had to but because they wanted to,” Soon said.

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