AUSTIN, Texas – Texas' first Hispanic female sheriff says she will run against Republican Gov. Greg Abbott in 2018.

Democrat Lupe Valdez has been the sheriff of Dallas County for 12 years. Her announcement Wednesday makes her the most prominent Democrat in the race after bigger names passed on trying to break Republicans' 22-year hold on the Texas governor's mansion.

The 70-year-old Valdez is an Army veteran and was Texas' first openly gay female sheriff. She's clashed with Abbott over federal immigration detainers and says opportunity is "out of reach" for many Texans.

Valdez will resign as sheriff to run for governor. She'll be an underdog in Texas, which hasn't elected a Democrat to a statewide office since 1994.

Several other lesser-known Democrats are also running. Abbott has no serious GOP challenger.

Here are 4 things to know about Valdez:

1. Lupe Valdez is serving her fourth term as sheriff after her first election 13 years ago in 2004, making her one of the most popular Democrats in North Texas.

2. Valdez is one of only two female sheriffs in the state and is the first openly gay, female Hispanic sheriff.

3. Valdez is the 8th child of migrant farm workers who went to college, served in the army and went on to become a federal immigration agent and a sheriff.

4. Valdez has clashed with Governor Abbott over the enforcement of the Sanctuary Cities law and jail policies.