KINGWOOD — Gov. Greg Abbott on Monday vowed to challenge Democratic gubernatorial candidate Lupe Valdez over her views on border security and immigration, emphasizing an early contrast with the former Dallas County sheriff who has not yet secured her party's nomination.

Abbott's comments drew a full-throated response from Valdez, who suggested the Republican incumbent "would rather spend his time sowing division than talking about his failed leadership."

Abbott offered his most extensive comments on Valdez's candidacy yet after a Tea Party meeting here Monday night, telling The Texas Tribune that he and she "have been locked in a battle for an aspect of Texas ideology" that goes back to their clash three years ago over her department's policy on compliance with federal immigration authorities. Like he did in a tweet earlier this month — when he broke his silence on Valdez's campaign — Abbott treated her as the Democratic nominee Monday, despite the fact she is in a May 22 runoff against Andrew White, the son of late Gov. Mark White.

"It’s clear that she’s not only obviously the frontrunner and had the most votes in the initial go-around, but it’s our analysis that she’ll be the nominee," Abbott said. "And so every time she comes out and starts talking about ways that are antagonistic to the Texas perspective on making sure that we ban sanctuary cities, secure our border, I’m going to challenge her on it."

Valdez opposes the state's ban on "sanctuary cities" — known as Senate Bill 4, or SB 4 — that Abbott signed into law last year, looking to punish local officials who do not fully cooperate with federal immigration authorities. She has also been critical of his decision to heed the call of President Donald Trump and send hundreds of National Guard troops to the border earlier this month — criticism that prompted Abbott's April 4 tweet declaring her his November opponent.

"I think she embodies the Obama approach, which is more open borders, obviously not enforcing the ban on sanctuary cities," Abbott said Monday. "We went through a big legislative process to make sure that Texas would pass a ban on sanctuary cities. If Lupe is elected, she will eviscerate that ban on sanctuary cities, and all these concerns that so many Texans have will be threatened."

Valdez fired back in a statement Tuesday morning, saying it's "back to business as usual with Greg Abbott spewing his fear-based open borders nonsense."

"I've spent 42 years working in law enforcement, working to keep Americans safe, I know what smart security looks like and this isn't it," Valdez said. "Demonizing immigrants, and spreading fear and hatred is exactly the wrong approach."

As for the "sanctuary cities" law, Valdez added, "You can bet this military veteran, former federal agent and four-term Sheriff of Dallas County is going to eviscerate SB 4."