Washington (CNN) Democrats have had the majority in the House of Representatives for just two months, but they've already been sidetracked by an ugly divide over anti-Semitism and other bigotry.

For weeks, tensions on Capitol Hill have risen over remarks from freshman Rep. Ilhan Omar of Minnesota questioning the allegiance of Israel supporters in Congress. Her comments drew condemnation from many of her fellow Democrats and prompted House Speaker Nancy Pelosi of California to push for a vote on a resolution condemning anti-Semitism.

Rather than putting the issue behind them, however, the move only prolonged the controversy and has drawn attention to divisions that erupted inside the party around a highly sensitive issue.

After Wednesday's vote was tabled following an ugly scrum that broke out among Democrats behind closed doors, on Thursday Pelosi confirmed the House would vote later in the day on a second, broader resolution that condemned not just anti-Semitism but Islamophobia and white supremacism as well.

The original resolution came after Omar criticized politicians by using anti-Semitic tropes, prompting condemnation from several Jewish Democratic lawmakers and an apology from Omar last month. But Omar later dug in when she suggested pro-Israel interests pushed members of Congress to pledge allegiance to a "foreign country," drawing further outrage from her colleagues.

Pelosi had a choice: She could issue piecemeal condemnations and hope the issue disappeared, or nip it in the bud with a strong resolution staking out the House's stance on anti-Semitism. She chose the latter but didn't count on the resistance from allies of Omar.

Pelosi now says the rewritten resolution does not mention Omar's name and said that she does not believe the 37-year-old first-term Democrat "appreciates the full weight" of her words. "I don't believe it was intended in an anti-Semitic way," Pelosi told reporters at her Thursday press conference. "But the fact is that's how it was interpreted and we have to remove all doubt as we have done over and over again."

Asked if Omar should apologize, Pelosi said, "It's up to her to explain."

Anger from the left

Members from both the Congressional Black Caucus and the younger, progressive wing of the party were furious about the leadership's gambit. They questioned singling out Omar for condemnation. What about bigotry from Republicans, including President Donald Trump? And why were Democrats so focused on a woman of color, one of just two Muslims in Congress? Could the added scrutiny even put Omar in danger?

"Like some of my colleagues in the Congressional Black Caucus, I am concerned that the spotlight being put on Congresswoman Omar may put her at risk," California Sen. Kamala Harris told reporters Wednesday. Sens. Bernie Sanders of Vermont and Elizabeth Warren of Massachusetts -- who like Harris are running for the 2020 Democratic presidential nomination -- also voiced their support for Omar.

Others on the left asked why Democrats were condemning only bigotry against Jews. "We think that hate and racism in our country is growing. American Jewish, LGBTQ, Latino, immigrant, Muslim -- it is something that needs to be looked at as a whole instead of just trying to come up with a hierarchy of hurt and pain," Rep. Rashida Tlaib of Michigan, another freshman Democrat and the other Muslim in Congress, told CNN on Wednesday.

Frustrated moderates

On the other side of the debate, moderate Democrats were frustrated that Omar's comments have derailed the agenda in the House and exposed divisions in an otherwise unified caucus. There are also concerns that a watered-down statement might end up looking like tolerance of anti-Semitic views within the caucus.

"One would think it would be a lot simpler than it appears to be to pass a resolution condemning anti-Semitism," Mark Mellman, a veteran Democratic pollster and founder of the Democratic Majority for Israel, told CNN. Mellman founded his group in January to shore up support in the party for the US-Israel relationship and to counterbalance what he sees as a rise in anti-Israel views among some Democrats.

The dispute is a leadership test for Pelosi and her ability to manage a majority built both from energized young progressives from the heart of the anti-Trump resistance and moderates elected on pocketbook issues in Trump country. But this isn't a debate about policy; it's about bigotry and whether the caucus will tolerate it or not. That's not a conversation the Democrats wanted to be having in public as they ramp up investigations into Trump and push forward their policy agenda.

"This is not a productive use of our time," a senior aide to a moderate House Democrat told CNN. "We need to change the subject and get back to the things we promised to do, which is infrastructure, health care, jobs."

The issue is the first real setback for a Democratic caucus that has largely remained a united front against Trump. From holding the line on the government shutdown to voting to rescind Trump's national emergency declaration, House Democrats have so far hung together. "Those were enormous wins, and now this makes it look like we are in disarray," said the senior aide.

That's even given Trump, who himself said there were "fine people" among the marchers in the 2017 neo-Nazi rally in Charlottesville, Virginia, an opening to criticize Democrats. "It is shameful that House Democrats won't take a stronger stand against Anti-Semitism in their conference," he tweeted Wednesday . "Anti-Semitism has fueled atrocities throughout history and it's inconceivable they will not act to condemn it!"

The longer Democrats fight over the party's stance on anti-Semitism, the greater the potential damage to the caucus. There's a cautionary tale unfolding across the pond, where Britain's Labour Party is being pulled apart by its own anti-Semitism issues. Several disaffected Jewish members of Parliament have left the party over Labour leader Jeremy Corbyn's perceived embrace of and tolerance for anti-Jewish sentiment.

"We can't be silent as Omar continues to say these things, because if we are silent, we're complicit in what is completely unacceptable," says Josh Block, a former Clinton administration official and head of the Israel Project, a nonpartisan pro-Israel group. "And the leadership needs to act before the virus of Corbynism infects the party."

A new paradigm

This isn't the first time House Democrats have grappled with internal divisions. For 40 years, the party held control of the House with a coalition of Southern segregationists, urban blacks and the white working class. During that time, it dealt with substantive issues including civil rights, the Cold War and tax revisions, to name a few.

What seems to be different this time is the way the party handles differences among its factions. In a way, that's a function of the rise of social media as a political tool, where communicating publicly to an online audience outweighs speaking privately to members of your coalition. It's worth noting that Omar set off this firestorm about Israel with a pair of tweets taking on members of her party for accepting money from Jewish-backed lobbying groups.

That disconnect between the new class and the old way of doing things was captured in the comments of 65-year-old Michigan Rep. Debbie Dingell. "What we need to do is not be out there Twittering," Dingell told reporters Wednesday. "We need to talk to each other."