Updated 9/29/17

Arizona Democratic Rep. Kyrsten Sinema announced Thursday that she is challenging GOP Sen. Jeff Flake in one of the few potential Senate pickup opportunities for Democrats in 2018.

EMILY’s List, and then the Democratic Senatorial Campaign Committee, quickly endorsed Sinema’s candidacy Friday morning, prompting one of her potential Democratic opponents to pass on the race.  

“I’m running for the United States Senate because I’m not giving up on the American dream,” Sinema said in a nearly three and a half minute YouTube video.

Flake is viewed as one of two vulnerable GOP senators running for re-election in 2018. Flake has faced criticism from Democrats and also from some Republicans, since he has been very critical of President Donald Trump. Trump won the state by 4 points in 2016.

State Sen. Kelli Ward has launched a primary challenge against Flake. Ward lost a 2016 primary campaign against Arizona’s senior senator, John McCain.

Inside Elections with Nathan L. Gonzales rates the race Tilts Republican.

Sinema could still face a primary opponent from the left, given that she has a centrist voting record. She also chairs the political arm of the Blue Dogs, a group of more conservative House Democrats.

But Dr. Randy Friese, a state legislator who was considering the race, announced late Friday morning that he would support Sinema’s Senate bid and run for re-election to the state House in 2018. Friese is a surgeon who treated former Rep. Gabby Giffords, who was shot in 2011 at a constituent meeting in Tucson.

Phoenix Mayor Greg Stanton, who is term-limited, was also considering a Senate run. But he has indicated he could run for Sinema’s House seat if she vacated the seat to run for Senate.

Sinema was first elected to represent the 9th District in 2012. She is a former state legislator. Sinema is also bisexual, making her one of two LGBT women in Congress.

In her video, Sinema highlighted her personal story, including part of her childhood where her family was homeless.

“I guess I’m a little bit different than most people in politics,” Sinema says into the camera. “…I never believed that being homeless was going to stop me from being who I wanted to be.”

She made a nod to her moderate attitude in the video, as well as her support for federal programs.

“The way I see it, the American dream is a combination of working hard, pulling yourself up by your bootstraps every day, but also reaching out to help people who need a hand,” Sinema said. She highlighted assistance from food stamps and federal college loan programs.

She said the answer to wanting to run for Senate is “easy.”

“I want to do more for my country,” she said.

Republicans indicated Thursday night that they plan to paint Sinema as a far-left candidate.

“Kyrsten Sinema has made it clear she’s too extreme and inexperienced to be in the U.S. Senate,” said Katie Martin, National Republican Senatorial Committee spokeswoman. Marin said Sinema “has more in common with the failed, radical leadership of Nancy Pelosi than she does with Arizonan families.”

Flake’s campaign spokesman, Will Allison, struck a similar tone in a statement Thursday night.

“From her time working on Ralph Nader’s campaign to the state legislature to Congress, Kyrsten Sinema has always been out-of-touch with Arizona and she’ll do anything to hide her progressive record,” Allison said.