"I feel like I have an obligation to reflect the voices of districts that don't look like the majority of our caucus,” Murphy said in an interview.

That position, along with several others that have won her no favors in the party, aren’t just about her own battleground district. The senior member of the moderate Blue Dog Coalition sees part of her role as throwing herself on political grenades for endangered members facing injurious votes, even if it means each of Murphy’s public stands against Speaker Nancy Pelosi and Biden reads like a threat to unravel her party leaders' agenda.

When Biden visited the House in early October, for instance, Murphy said afterward that she was stunned by the president’s decision not to prod members to vote for his infrastructure plan that day. Instead, he bowed to progressive pressure and green-lighted a delay on the infrastructure bill.

“He took what would have otherwise been a historic, bipartisan win and turned it into a partisan cudgel against his own party,” Murphy said.

The Florida Democrat has embraced this more confrontational role amid questions about her own political future, weighing her options as she faces a likely tough redistricting battle to keep her seat. While once seen as certain to run for Senate in 2022, she opted out of a brutal primary battle to challenge Sen. Marco Rubio (R-Fla.) and could turn her sights to a 2024 race for the upper chamber, according to people close to her.

“I try to handle things outside of the glare of the media,” Murphy said, adding she feels protective of her fellow moderates “because oftentimes decisions are made and they don't take into account what a purple or red or marginal blue seat looks like.”

The real-talking centrist mantle that Murphy’s now donning in the House was once worn by a lawmaker now known more for her silence: Sen. Kyrsten Sinema (D-Ariz.). Before Sinema moved from the House to the Senate in 2018, she was a swing-state scrapper who defended Murphy when leadership pressured her to take a tough vote.

When Democrats tried to corner Murphy on a tough vote, the Florida Democrat recalled Sinema stepping in to privately tell her: “You do what you need to do.”

Like Sinema, Murphy has an independent streak, a distaste for cable TV antics and is something of an enigma to many of her colleagues from deep blue districts.

"If you want to break out of partisan stalemate and achieve lasting results for our country, you want Stephanie Murphy on your side,” Sinema said in a statement to POLITICO. “Stephanie is a tireless, well-prepared, and — above all else — independent voice for her state.”

Some Democrats have privately grumbled that Murphy and her fellow moderates have gummed up the works on Biden’s broader spending plan, like when she and three other centrists voted against parts of his bill in committee this summer. They point to Murphy’s role on Pelosi’s whip team and her seat on the speaker's hand-picked panel investigating Jan. 6 as reasons they were surprised by her public criticism.

But Murphy dismissed the notion that any plum committee spot should mean curbing any of her public or private statements: “Had someone offered me the January sixth committee in exchange for some future vote. I wouldn't be on that committee.”

Murphy’s allies also point out that she has played a key role in quietly shaping legislation and building consensus across the Democrats’ centrist bloc for years, usually preferring to work behind the scenes with Pelosi, House Majority Leader Steny Hoyer (D-Md.) and other leaders.

The decision to speak out more publicly this year was, in part, because the House’s centrist bloc felt that it needed a counterweight to the House’s larger and more vocal progressive wing as Biden’s agenda moved through the Hill.

“She’s never been shy,” said Rep. Kurt Schrader (D-Ore.), another co-chair of the Blue Dog Coalition. “I think there are very few people who fit into the Murphy mold of putting, frankly, the country and the district ahead of the party allegiance... She walks that talk.”

If Murphy does stay in the House, other Democrats have speculated that she could have a place in the next generation of leaders. They point to her compelling personal story as a Vietnamese refugee who went on to work at the Pentagon and the trust she’s built among vulnerable members.

“Stephanie Murphy is a smart, hardworking, thoughtful and principled leader within the House Democratic Caucus and her voice matters,” said caucus Chair Hakeem Jeffries (D-N.Y.). He added that her victory in 2016 helped form “one of the building blocks” to Democrats taking back the majority two years later.

Yet it wasn’t always clear that she would seek reelection to the House next November.

In the first few months of this year, Murphy had all but declared a statewide run against Rubio, only to back down after her Florida colleague, Rep. Val Demings (D-Fla.), announced her run.

Since then, Murphy has committed to seeking reelection in the House. But a subpar fundraising haul in recent months — just $140,000 in the last quarter — left some wondering whether she’d changed her mind. People close to Murphy said she has no plans to ditch her reelection bid, though they acknowledge her seat could become much tougher to hold in Florida’s GOP-controlled redistricting process. Allies such as Rep. Scott Peters (D-Calif.) said that “if she wants to run, she’ll have all the resources that she needs.”

Murphy still insists that Democrats can keep their majority next November with the right strategy — one that she is working to help retool after the previous year’s election cost the seats of dozens of moderates. Even before November 2020, Murphy and her team were ringing some alarm bells, particularly in her home state of Florida, where she worried Democrats were losing ground with the Latino voters.

Outspoken against socialism, Murphy cut an ad for the Biden campaign’s 2020 race in south Florida, far outside her own district, in an attempt to shore up support for her party there. This year, she and her team say they’re devoting more resources to helping protect incumbents.

Murphy believes Biden’s agenda could be a key factor in Democrats holding onto power, a key reason why she has continued to raise issues with the broader $1.75 social spending plan.

“No amount of money can overcome bad policy. And so no amount of messaging, no money spent, can overcome messaging that is inconsistent with what constituents want,” Murphy said.

It’s that concern that has led the Florida Democrat to take such a public — and at times, combative — role in negotiations. This summer, Murphy was among roughly 10 Democrats who held up Biden’s social spending bill to secure a vote on a bipartisan infrastructure bill.

But plans for that late September vote were ultimately scuttled, thanks to a counter-threat from progressives to block the infrastructure bill without the more sweeping bill. That deepened the trust gap that many centrists have felt with leadership this fall, and further inflamed tensions across the party.

Months later, much of the dynamics remain the same: Progressives and centrists have offered competing demands, only to see none of Biden’s bills passed. Meanwhile, Murphy argues that those progressive maneuvers have only led to delaying the infrastructure vote — with no tangible change in the Senate centrists’ position.

“Sen. Manchin is not one red cent above where he was in July,” Murphy said.

Heather Caygle and Burgess Everett contributed to this report.