In the final hours before the filing deadline on Dec. 9, Sima Ladjevardian arrived at the Harris County Democratic Party office in Houston to make a little bit of news: She was running for Congress.

The prominent Houston lawyer, Democratic activist and fundraiser, and former Beto O'Rourke adviser had been thinking about running for a while but had thrown herself into O'Rourke's presidential campaign, which did not wind down until mid-November.

"It really wasn't much time," she said in an interview Tuesday. "I just went in and did it then."

Now Ladjevardian's candidacy is shaking up the primary for a seat that Democrats consider more flippable than some think — and held by a high-profile target no less: rising star and former Navy SEAL Dan Crenshaw, R-Houston. About an hour and a half after Ladjevardian announced she was running, O'Rourke endorsed her. The next morning, the 2018 nominee for the seat, Todd Litton, made clear he was supporting her. And 48 hours after filing, she announced she had already raised over $200,000.

In making the last-minute entry, Ladjevardian charged into a primary that already featured two candidates, including one who has been running since February, Navy veteran Elisa Cardnell.

"It wasn't a complete surprise," Cardnell said of Ladjevardian's entrance. "I welcome her to the field, but since day one, this has been about how we hold Dan Crenshaw accountable for his voting record. Honestly, I'm just glad more folks are seeing what we knew back when we launched — that Dan Crenshaw is not safe in Texas 2 and this is a winnable race."

The 2nd District is not among the six seats that the Democratic Congressional Campaign Committee has prioritized flipping this cycle in Texas, but Democrats have ample reason to believe it is within reach. Litton lost by 7 percentage points in 2018, despite no significant national investment on his behalf and Crenshaw rocketing on to the national stage a few days before the election after "Saturday Night Live" star Pete Davidson mocked his war wound. At the same time, the U.S. Senate nominee, Beto O'Rourke, lost the district by just a point.

The DCCC is nonetheless paying some attention to Crenshaw, targeting him in a statement for this story over his vote last week against a prescription drug price bill.

Still, Crenshaw will not be easy to topple. His star has only risen in Republican politics since his 2018 election, and he has a hefty $1.6 million stockpile for his reelection campaign. That campaign said in a statement that his Democratic opponents are only focused on "gaining power and attacking" him while he focuses on constituents' concerns.

Ladjevardian, who is Iranian-American, left the country during the Iranian Revolution in the late 1970s and says she is running because she wants everyone to have a shot at the American Dream like she did once she got to the United States. A cancer survivor, she's emphasizing her firsthand experience with the health care system, saying she supports "keeping private insurance and choice and having Medicare cover the rest" but not Medicare for All. On gun violence, an issue that animated O'Rourke's White House bid, Ladjevardian said she backs proposals such as universal background checks and an assault weapons ban but stopped short of endorsing the mandatory buyback program championed by O'Rourke.

When it comes to her primary competition, Ladjevardian said it is "exciting" to have three candidates running but made clear she believes her experience makes her uniquely suited to bring together Democrats and Republicans and appeal to the district's diversity.

While Cardnell's fundraising has been modest for a potential battleground district — she raised $178,000 through the third quarter of this year — she has accrued several noteworthy endorsements, including U.S. Rep. Marc Veasey of Fort Worth, a DCCC regional vice-chair, and U.S. Rep. Veronica Escobar of El Paso, O'Rourke's congressional successor and longtime political ally. Cardnell and her supporters are emphatic about what they see as her primary advantage, saying that to defeat Crenshaw, it is going to take "a veteran who can go toe-to-toe with him."

The other Democrat who was already running before Ladjevardian declared, Travis Olsen, entered the primary much more recently — early November — but also brings a unique story rooted in public service: He worked for the Department of Homeland Security for over a decade before quitting in outrage at the Trump administration's immigration policies.

"I've been a front-line civilian in the federal government and have seen firsthand what the Trump administration has done," Olsen said in an interview. "I literally gave up my career because of my beliefs and convictions" — and Washington, he added, needs more people willing to do the same.

Yet Ladjevardian's entrance could complicate the other Democrats' best-laid plans, at least when it comes to her fundraising prowess and backing from O'Rourke. Since ending his presidential campaign in early November, O'Rourke has become more active in down-ballot races in Texas, including wading in to intraparty contests. During a political appearance Tuesday in Katy that Ladjevardian attended, O'Rourke told reporters that he was not concerned about alienating other Democrats with his endorsements, describing his decision to endorse Ladjevardian as a no-brainer.

"With Sima, not only has she been such an extraordinary supporter of mine, but I saw in the 2018 Senate race her exceptional organizing skills for us in southeast Texas, her tenacity, her work ethic, and I just think she would make an excellent member of Congress," O'Rourke said. "So for me, that was a very easy decision, and it does nothing to diminish the efforts of other candidates, it’s just that there’s somebody who I think is just clearly superior."

Ladjevardian's primary rivals are not interested in making an issue out of O'Rourke, with Olsen saying he is focused on earning the "endorsement of the voters in the district." And Ladjevardian said that while she was grateful for O'Rourke's support, "if I don't do the work, I don't think [it] means anything."

Republicans are more eager to capitalize on O'Rourke's involvement in the race. One of Crenshaw's fellow freshmen, Plano Republican Rep. Van Taylor, sent a fundraising email Wednesday for Crenshaw casting the race as "Dan Crenshaw vs. Beto O'Rourke" and warning that O'Rourke helped Crenshaw's "liberal democrat opponent" quickly raise $200,000.

One possible liability facing Ladjevardian in the primary is an aberration in her prolific political giving. She has historically donated overwhelmingly to Democrats, but in 2007 she gave a maximum donation to then-Republican presidential candidate Rudy Giuliani. The former New York City mayor now serves as President Donald Trump's personal attorney — and a central figure in the events leading up to the president's impeachment Wednesday.

In the interview, Ladjevardian emphasized she has given "sweat, blood, tears and anything else" to Democrats but acknowledged the Giuliani contribution, suggesting she made it out of respect to an elder in the Iranian-American community who was supporting Giuliani.

"Giuliani then is not Giuliani now," she said. "If it was Giuliani now, it would've been, 'Hell no.'"

Her primary competitors declined to comment on the donation. Cardnell said she is "not here to speak ill of other Democrats" and would leave the issue up to voters.

In any case, Houstonians will likely learn more about the race in the coming weeks as the Democratic candidates jockey to distinguish themselves and sharpen their cases against Crenshaw. They got their freshest fodder last week with Crenshaw's vote against the Democrat-championed bill to let Medicare negotiate drug prices, an idea he supported as a candidate. Crenshaw "caved to the drug company lobbyists and put wealthy special interests ahead of hardworking families," DCCC spokesman Avery Jaffe said in the statement.

Crenshaw's office has acknowledged he changed his position, citing concerns with the "heavy hand" of price negotiation. And in his campaign's statement, spokeswoman Kerry Rom said that among the issues he was focused on was lowering drug prices "while protecting American innovation."