Rep. Kyrsten Sinema, a moderate Democrat from Arizona, has announced that she is entering her state’s Senate race, boosting her party’s odds of potentially winning the seat. The third-term congresswoman announced her candidacy Thursday night in a video that emphasized her economically difficult upbringing. The seat is held by Jeff Flake (R-AZ), a staunch conservative who has also been one of the Republican Party’s more vocal Donald Trump critics. It is partially because of that criticism that Flake’s standing is tenuous in Arizona. And it’s unclear if he will be able to make it through his own party’s primary, in which he faces a challenge from Tea Partier Kelli Ward, who has the backing of a pro-Trump super PAC. Sinema is often described as nonconformist who, among other breaks with her party, refused to vote for Rep. Nancy Pelosi for Speaker. But her voting record is reliably moderate-Democratic, including support of gun control and immigration rights. She also is the first openly bisexual member of Congress. National Democrats had wanted her to enter the race and believe Arizona is essentially in their long-shot efforts to recapture the Senate.