Freshman Rep. Rashida Tlaib’s Twitter bio declares her the “Unbossed Congresswoman” for Michigan’s 13th District.

While the moniker has roots in Shirley Chisholm’s successful campaign to become the first black congresswoman, nowadays it also could be seen as a blunt message to Democratic leadership: Nobody is bossing around the class of 2019.

And that’s a problem for party bosses.

DEM FROSH TURN TABLES ON ANTI-SEMITISM REBUKE

On everything from the Green New Deal to impeachment to criticism of Israel, a squad of first-year congresswomen are flexing their muscle and posing an implicit challenge to Democratic honchos like Speaker Nancy Pelosi. Their stridently liberal agenda – and power to steer the national conversation via social media and press attention – has fueled tensions inside the party tent that in turn are testing leadership's control while stirring political concerns going into 2020.

“All of our problems are caused by three people,” one senior House Democrat lamented to Fox News.

That would be New York Rep. Alexandria Ocasio-Cortez, Minnesota Rep. Ilhan Omar and Tlaib – all freshmen, and all uniquely unencumbered by things like decorum or deference to party elders.

Ocasio-Cortez recently made waves by appearing to warn Democrats who vote with Republicans that they’re “putting themselves on a list” of possible primary targets (though she later denied she intended such a threat).

MODERATE DEMS FUME OVER OCASIO-CORTEZ 'LIST' THREAT

Tlaib famously made headlines upon taking office by vowing they’d “impeach the motherf---er,” in reference to President Trump. Pelosi this week tried to rein in the impeachment chatter, taking a firm public stance against that route. Yet in the immediate aftermath of Tlaib’s vow, Pelosi downplayed the hubbub, saying she wouldn’t use that language but it’s nothing worse than Trump has said.

'All of our problems are caused by three people.' — Senior House Democrat to Fox News

Fast-forward to this month, and Pelosi faced another discipline problem – concerning Omar.

Fresh off a dispute that saw Pelosi and fellow Democratic leaders condemn the Minnesota congresswoman for suggesting American allies of Israel were financially motivated, Omar riled party leaders again after suggesting Israel supporters expect or seek “allegiance” to the Jewish state. The statement was widely condemned, including among senior Democrats, as echoing the age-old “dual loyalties” smear against Jewish politicians.

“I am saddened that Rep. Omar continues to mischaracterize support for Israel,” New York Democratic Rep. Nita Lowey tweeted at the time.

Leaders hastily prepared a resolution to push back on anti-Semitism. Yet after Pelosi faced a rebellion in the ranks amid concerns the measure would unfairly single out Omar, a Muslim, and increase security threats against her (she was recently the subject of an inflammatory poster at the West Virginia capitol falsely tying her to the 9/11 attacks), the resolution was overhauled.

The result was a broad rebuke of bigotry, including anti-Semitism as well as “anti-Muslim discrimination and bigotry against minorities” perpetrated by white supremacists and others. The resolution condemned “dual loyalty” accusations, but did not mention Omar by name.

DEM FROSH TURN TABLES ON ANTI-SEMITISM REBUKE, SHIFT SPOTLIGHT TO ISLAMAPHOBIA AND AIPAC POWER

Republicans claimed the end product was watered down.

“Clearly, Speaker Pelosi is afraid of some of the fringe elements on the socialist left, and that was on full display,” House GOP Whip Steve Scalise told Fox News.

The sequence of events only fed the narrative that party leaders are struggling to rein in freshman lawmakers who are pulling Democrats off message at a critical time, with the 2020 presidential campaign season getting underway.

A frustrated senior House Democratic aide told Fox News last week: "Here we are again, fighting with ourselves. I've spent another week dealing with this and not on policy."

The handling of the resolution exposed Democrats to barbed accusations from Republicans, with Trump calling them the “anti-Jewish party.” Senate Minority Leader Chuck Schumer, D-N.Y., who is Jewish, fired back by noting Trump’s infamous 2017 comments blaming both sides for violence at a white supremacist rally in Charlottesville: "Mr. President, you have redefined chutzpah."

But the party is dealing with fallout on other fronts as well.

Ocasio-Cortez has led the charge on the Green New Deal, a sprawling plan that would aim to transition the country to renewable energy while instituting numerous government-heavy programs including guaranteed jobs. It has won endorsements from virtually all top-tier Democratic presidential candidates.

While far-reaching and controversial on its own, however, the resolution’s rollout was marred by FAQs from the congresswoman’s office which apparently were not ready for prime-time and that included items like “economic security” for those “unwilling to work.”

Instantly, the language fueled Republican allegations that Democrats’ 2020 vision is one of rampant socialism that would fundamentally upend the American system, even as the sponsors tried to downplay the FAQs. The party has used the “socialism” brush to paint virtually the entire presidential field. Setting the narrative, the issue became a dominant theme at this year’s Conservative Political Action Conference – with White House economic adviser Larry Kudlow calling to “put socialism on trial.”

LARRY KUDLOW ROUSES CPAC WITH CALL TO 'PUT SOCIALISM ON TRIAL'

In a new column for The Atlantic, Chicago Democratic Mayor Rahm Emanuel cited these kinds of attacks in imploring the party, "If Trump's only hope for winning a second term turns on his ability to paint us as socialists, we shouldn't play to type."

Meanwhile, Pelosi has urged caution with regard to another politically explosive issue: impeaching Trump.

In a fresh interview with The Washington Post Magazine, she declared outright she’s “not for impeachment.”

The issue, she said, is so “divisive to the country that unless there’s something so compelling and overwhelming and bipartisan, I don’t think we should go down that path, because it divides the country. And he’s just not worth it.”

Yet Tlaib and Omar already have signed a pledge to impeach Trump. And, around the same time anti-Trump protesters were arrested outside Pelosi’s office last week, Tlaib assured them she’ll introduce a resolution this month urging the Judiciary Committee to proceed with impeachment.

IMPEACHMENT DRUMBEAT BUILDS ON LEFT, AS HOUSE SHIFTS PROBES INTO HIGH GEAR

Asked Monday about the Democratic members who would chafe at Pelosi's impeachment brush-off, House Majority Leader Steny Hoyer, D-Md., assured: “We’ve got 62 new members. Not three." On Tuesday, Hoyer acknowledged those three are “newsworthy,” but also said “the distraction [from impeachment] would be major.”

For their part, the freshmen have argued they’re unfairly scrutinized, even likening the treatment to that experienced by Chisholm. Ocasio-Cortez told Fox News last week that the freshman Democratic women of color are “being treated [differently] and targeted.”

Looking ahead, some Democrats stress that it’s critical for the party to maintain focus.

“There’s always going to be distractions. It’s 435 people who are really their own boss, and they’re able to say whatever they want,” freshman Rep. Katie Hill, D-Calif., told “Fox News Sunday,” with regard to recent controversies in the caucus. “So, I think what we have to figure out what to do is to say, okay, this isn’t the views of everybody in Congress … but how do we maintain focus on our agenda as a whole?”

Rep. Ben McAdams, D-Utah, speaking on “Sunday Morning Futures,” said the caucus has actually “moved to the center” – it’s just that those watching the media coverage might not realize that “because some of the more progressive members are far more outspoken.”

McAdams, who represents a deep-red state, played up the importance and influence of Democratic moderates in Congress.

But Ocasio-Cortez pulled no punches in letting the world know what she thinks of moderates, in a fiery appearance at the South by Southwest festival in Austin.

CLICK HERE TO GET THE FOX NEWS APP

“Moderate is not a stance. It's just an attitude towards life of, like, ‘meh,’” the New York Democrat said Saturday.

At the same summit, despite the pleas of veteran operatives like Emanuel not to play into Trump's paint-them-socialist strategy, the unbossed Ocasio-Cortez all but handed him the brush. "Capitalism is irredeemable," she declared.

Fox News’ Brooke Singman, Gregg Re and Mike Emanuel contributed to this report.