Texas Elections 2018 More in this series

*Editor's note: This story has been updated throughout.

Dallas County Sheriff Lupe Valdez announced Wednesday morning that she is running for governor, giving Texas Democrats a serious candidate for the top job with five days until the candidate filing deadline for the 2018 primaries.

"Like so many hardworking Texans, I know it’s tough deciding between buying food, finding a decent place to live, and setting aside money for college tuition," Valdez said in a statement before filing at the Texas Democratic Party headquarters in Austin. "Opportunity in Texas ought to be as big as this great state, but it is out of reach for far too many, that’s why I’m running for Texas Governor. I’m a proud Texas Democrat. I believe good government can make people’s lives better, and I intend to do just that."

Addressing reporters after filing, Valdez used a mix of English and Spanish as she denounced state GOP leaders for "putting a spin on lies and creating fear," particularly when it comes to undocumented immigrants.

Until Wednesday, six little-known Democrats had filed to challenge Republican Gov. Greg Abbott, who is seeking a second term in 2018. Andrew White, the son of late Gov. Mark White, has been exploring a run for weeks and is set to announce his campaign Thursday in Houston.

Any Democrat running for governor faces a steep climb against Abbott, who easily defeated the party’s 2014 nominee, Wendy Davis, and has built a $40 million-plus war chest for re-election. Texas has not elected a Democrat to statewide office in over two decades.

Speaking with reporters after filing, Valdez said she was undaunted by the challenge, particularly when it comes to fundraising.

"I think we're going to raise whatever money's necessary. I don't believe that we need 40, 60, 90 bazillion dollars," Valdez said. "Abbott may have the money — we're going to have the people."

Republicans responded to Valdez's candidacy by ridiculing her as the Democrats' last-ditch choice for governor. Abbott's campaign released a video showing a fake online dating website — "DHarmony" — where a user fails to match with 10 potential candidates before landing on Valdez.

"It’s been a merry-go-round for the Texas Democrat Party in their pursuit for a candidate for governor, and after a dizzying search, they have finally fielded a team of far-left liberals ready to battle in the primary," Abbott campaign spokesman John Wittman said in a statement.

"Regardless of who Texas Democrats ultimately nominate for governor, our campaign will be prepared to run on Governor Abbott’s record and policies that have led to more jobs created in Texas in the past year than any other state, the best business climate in America and record low unemployment."

Hours after Valdez announced she was running, Abbott's team released a re-election endorsement from a law enforcement group in her backyard: the Dallas Police Association. Valdez brushed off the endorsement, suggesting to reporters that it does not reflect the view of the full membership of the association.

Valdez is serving her fourth term as sheriff of Dallas County, the second most populous county in the state and a Democratic stronghold. She drew national attention when she was first elected in 2004 as the nation’s first openly gay female Hispanic sheriff.

Abbott and Valdez are not unfamiliar with one another. In 2015, they butted heads over her department’s policy regarding compliance with federal immigration authorities — a debate that later cropped up in Travis County and became the driving force behind the “sanctuary cities” bill that Abbott signed into law earlier this year.

Under the Texas Constitution, certain elected officials, including sheriffs, must immediately step down once they declare their candidacy for another office. After Valdez announced her campaign for governor, her office said she had "submitted her resignation today," releasing a letter dated Nov. 28 that said she was stepping down as of Wednesday.

Valdez told The Texas Tribune a month ago that she was looking at the possibility of challenging Abbott. Talk of Valdez running for governor heated up last week, when Dallas media reported she had submitted her resignation ahead of a likely bid. Her office denied that, saying she was still "considering the next stage in her career."

Republicans pounced on the confusion, questioning whether Valdez was defying the state constitution's "resign to run" provision.

While Abbott’s campaign did not immediately weigh in on Valdez’s run, Texas GOP Chairman James Dickey chimed in with sarcastic praise, issuing a statement that congratulated his Democratic counterpart for "finally finding a candidate willing to enter the gubernatorial race."