Valdez, the state's first Hispanic female sheriff and the state's first openly gay sheriff, says she stepped down from the job Wednesday morning so she could run for statewide office.
"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.
"I'm stepping up for Texas, for everyone's fair shot to get ahead, I'm in", Valdez said. "I believe good government can make people's lives better, and I intend to do just that".
Valdez is serving her fourth term as sheriff of Dallas County, the second most populous county in the state and a Democratic stronghold.
Valdez resigned as sheriff as she filed.
In 2015, Valdez got crosswise with Abbott when she announced her department would decide whether to turn over undocumented offenders to federal immigration authorities on a case-by-case basis.
Earlier this month, Valdez told the Texas Tribune that she was "in the exploratory process" of starting a gubernatorial run.
"I think everybody feels like a sacrificial lamb at this point, nobody expects to run and win", said Henson.
Speaking with reporters after filing, Valdez said she was undaunted by the challenge, particularly when it comes to fundraising.
Republicans said Wednesday her positions will make her an easy target for Abbott, who polls show riding a wave of popularity despite his support of several divisive issues during this year's legislative session, including the so-called bathroom bill that pitted conservatives against business interests in Texas.
Others who have filed as Democrats to challenge Abbott include Houston electronics businessman Joe Mumbach, Dallas financial analyst Adrian Ocegueda, retired Flint teacher Grady Yarbrough, former Balch Springs mayor Cedric Davis Sr. and San Antonio businessman Tom Wakely.
Jones noted that an "ideal candidate" would be someone with more name recognition, such as Julián or Joaquin Castro, but that Valdez "is a second-best option". "While he hasn't run for public office before, he is kind of playing that middle field to try to attract moderate voters in the Democratic Party but more so moderate voters on the Republican side, as well as independent voters". Abbott has a $40 million campaign war chest and Texas hasn't elected a Democrat statewide in more than two decades. But then again, who would have imagined a generation ago that a gay Latina would become a four-term sheriff presiding over the state's second-largest county? "Abbott may have the money - we're going to have the people".
After attaining the rank of captain in the U.S. Army, Valdez went on to work as a federal agent for U.S. Customs and Border Protection and, later, the Department of Homeland Security, focusing on fraud and drug cases for nearly 30 years before being elected sheriff of Dallas County, the state's second most populous county. I don't believe that we need 40, 60, 90 gazillion dollars.
"We helped build trust in the community", said Valdez. "I think we'd be a great match".