MJ Hegar poses for a portrait at her home in Round Rock, Tex., in 2018. (Eric Gay/AP)

MJ Hegar, a Democratic military veteran who fell short last year in a high-profile bid to unseat a Republican congressman in a conservative Texas district, announced Tuesday that she will try to topple the state’s senior senator, John Cornyn (R), next year.

“Unseating an entrenched incumbent senator is going to be tough, but I’ve faced worse odds in my life,” Hegar wrote on Twitter. “Saddle up, Texas. I’m in.”

Hegar, a former Air Force helicopter pilot, referenced the hard-fought race she lost last year by less than 3 percentage points in an announcement video in which she said she did not “get a pilot slot my first time trying.”

In the video, Hegar, who proved a prolific fundraiser in her House race, also sought to tie Cornyn to Senate Majority Leader Mitch McConnell (R-Ky.), referencing Cornyn’s service in the No. 2 Republican leadership position in the chamber.

“For those of you who don’t know Sen. John Cornyn, he’s that tall guy lurching behind Mitch McConnell in basically every single video,” Hegar said. “He calls himself Big John, but he shrinks out of the way while Mitch McConnell gets in the way of anything actually getting done in our government.”

Cornyn first won election to the Senate in 2002. He easily prevailed in his last bid for reelection in 2014 with more than 61 percent of the vote.

In a statement, Cornyn’s campaign referred to Hegar as “Chuck Schumer’s handpicked candidate,” a reference to Senate Minority Leader Charles E. Schumer (D-N.Y.)

“Texans rejected her radical views once and they will again,” the statement said of Hegar.