The Hawaii delegation in Congress has long been known as one of the most tightly-knit in Washington, but that tradition was shattered this week when Rep. Tulsi Gabbard publicly criticized fellow Democrat Sen. Mazie Hirono's questioning of a judicial nominee.

Gabbard, who announced Friday that she has decided to run for president in 2020, made headlines and provoked an irritated response from Hirono earlier in the week by implicitly accusing the senator and other Democrats in an op-ed published in The Hill of having "weaponized religion for their own selfish gain" in their questioning.

While Gabbard did not mention Hirono by name, her fellow Hawaiian clearly saw the op-ed as friendly fire.

Hirono, an outspoken critic of President Trump, returned fire in a statement that dinged Gabbard for giving ammo to Trump's right-wing allies.

"Over the past two years, the Senator has been attacked by right wing ideologues for her examination of Donald Trump's ideologically-driven nominees to the courts. It is unfortunate that Congresswoman Gabbard based her misguided opinion on the far-right wing manipulation of these straightforward questions," Will Dempster, Hirono's spokesman, said in a statement.

A spokeswoman for Gabbard did not respond to a request for comment.

Gabbard spokeswoman Lauren McIlvaine in a statement to The Washington Post said Gabbard will "always fight for religious freedom and oppose religious bigotry - no matter where it comes from or to whom it's directed."

"Congresswoman Tulsi Gabbard respects Senator Hirono," McIlvaine said. She added that "no nominee for public service should be disqualified, either directly or indirectly because of their religion or religious affiliation."

The criticism of her fellow Democrats - including her home state senator -was a bold move by Gabbard and seen by political observers in Hawaii as gearing up for a White House campaign.

"I suspect the editorial was written in conjunction with the plan to announce her run for president," former Hawaii Gov. Neil Abercrombie, who served 19 years in Congress, told The Hill. "People who support her presidential campaign probably think it will be helpful, but I'm not sure."

Gabbard said in an interview to be aired by CNN on Saturday that she will run for president and will make a formal announcement within the next week.

Gabbard may not have the national prominence to win the Democratic nomination outright, but she could be a top choice as a vice presidential pick if she can demonstrate the ability to woo pivotal Catholic voters. They were a crucial swing constituency in 2016 and are likely to be so again in 2020.

Colin Moore, director of the Public Policy Center at University of Hawaii Manoa, said Gabbard could be trying to distance herself from the rest of her delegation.

"You could characterize her as an independent thinker or a bit reckless," he said. "It may also be personal to her. She's a Hindu and her father is quite religious."

Whatever the reason, it made shock waves in Hawaii.

"Not only does it break conventional wisdom, it's very strange for someone in the Hawaii delegation to do this. They really think of themselves as a team and there's this expectation among voters that they'll operate as a team," Moore said. "A criticism like this is unheard of."

Hirono didn't comment on what might be motivating Gabbard, though she did not discount the role of the 2020 race.

"Other people have made that suggestion," Hirono told The Hill. "I'm not inside her head but what I do know is that her piece has resulted in all these alt-right groups that have been criticizing me for quite a while now over my questioning as to the fairness of these nominees - the alt-right groups are flocking to her defense. So if that's what she wanted that's what she's getting."

Gabbard criticized Democrats on the Senate Judiciary Committee for questioning Trump nominee Brian Buescher's fitness to serve on the U.S. District Court for Nebraska because of his strongly held Catholic beliefs.

Hirono sits on the committee and her written questions to Buescher includes whether he would recuse himself from a case related to abortion rights, and whether he intended to end his membership with the Knights of Columbus to avoid an appearance of bias in legal decisions.

Gabbard saw the questions about Buescher's membership in the Knights of Columbus as thinly-veiled anti-Catholicism, a view shared by many conservatives following the debate.

"If Buescher is 'unqualified' because of his Catholicism and affiliation with the Knights of Columbus, then President John F. Kennedy, and the 'liberal lion of the Senate' Ted Kennedy would have been 'unqualified' for the same reasons," Gabbard wrote in her op-ed.

Gabbard also targeted Sen. Dianne Feinstein (Calif.), the senior Democrat on the Judiciary panel, for challenging Amy Coney Barrett, Trump's nominee to the 7th Circuit Court of Appeals, on her strongly held religious views.

"No American should be asked to renounce his or her faith or membership in a faith-based, service organization in order to hold public office," Gabbard argued in her op-ed.

The column sparked an uproar in the normally tranquil world of Hawaii's congressional delegations, where lawmakers traditionally work together to steer federal dollars to Hawaii.

Hirono told The Hill that Gabbard has mischaracterized the nature of her opposition to Trump's nominees.

"I'm sorry she didn't call me so that I could have set her straight about the concern she had," she said.

Hirono explained that her sharp questioning of Trump nominees is not motivated by bias against religious convictions but instead concern that they are giving more weight to their personal views than the law.

"All of these Trump nominees that come before our Judiciary Committee for lifetime appointments, come having taken very strong positions on issues such as a woman's right to choose, LGBTQ rights, all of that - contrary to Supreme Court decisions, by the way," she said. "I want to make sure through my questioning that they can set aside their very strongly held ideological perspectives to be fair and impartial with their lifetime appointments."

Hirono said she had issued a statement but not reached out directly to Gabbard after the op-ed appeared.

Abercrombie said Gabbard articulated a valid principle, that people should not be held back from government service because of their religious views.

But he said Hirono was also right to make sure that Trump's nominees aren't so biased in their political views as to render them incapable of making impartial decisions.

"I wasn't born when Al Smith was attacked for his Catholic beliefs but I remember John Kennedy going to Houston," he said, referring to the Democratic presidential nominee who was attacked over his Catholicism in the 1928 presidential race.

Kennedy, a Catholic, spoke about religious tolerance and separation of church and state to the Greater Houston Ministerial Association during the 1960 presidential campaign.

"I understand the principle but it's unfortunate that it's devolved into personalities in the context of Sen. Hirono," Abercrombie said. "I'm saddened that it's being seen as directed at Sen. Hirono."

But he added, "Tulsi Gabbard would never intend to be unfair."

Gabbard won a national spotlight during the 2016 presidential primary as one of the few Democrats in Congress willing to serve as an outspoken advocate for Sen. Bernie Sanders (Vt.), an independent who gave Hillary Clinton a surprisingly tough race for the Democratic nomination.

While most of the Democratic establishment backed Clinton, Gabbard stepped down as a vice chairwoman of the Democratic National Committee to endorse Sanders after clashing with committee colleagues over a debate schedule that appeared to favor Clinton.

Hawaiian political experts think Gabbard carefully weighed the column before publishing it in a D.C. forum.

"I know that Gabbard is a very cautious politician and doesn't take stands on a whim, so I would expect that she has some polling research to back up her stand and attacks," said Richard Borreca, a political columnist at the Honolulu Star-Advertiser.

Gabbard has surprised the Democratic political establishment before.

In January 2017, she revealed she met with Syrian leader Bashar Assad, a move that angered politicians in both parties who questioned the appropriateness of sitting with a figure accused of gassing his own people.

Gabbard said she felt it was important for anyone interested in bringing peace to Syria to meet with those, like Assad, who might end the long Syrian war.