Willie Nelson fans are upset with the singer over the news that he’s not only supporting a Democratic Senate contender, but is headlining a rally in Texas for him.

Nelson announced on his Facebook page that he’ll be headlining the Turn Out For Texas rally for candidate Beto O’Rourke, who is running against Sen. Ted Cruz.

As Austin360 reported, Nelson brought O’Rourke on stage during his Fourth of July Picnic summer concert. Now he’s doubling down on his support by joining Joe Ely, Carrie Rodriguez, Tameca Jones and his two sons, Lukas and Micha Nelson, at the Sept. 29 rally.

“My wife Annie and I have met and spoken with Beto and we share his concern for the direction things are headed,” Nelson said in the press release provided to the outlet. “Beto embodies what is special about Texas, an energy and an integrity that is completely genuine.”

Beto O'Rourke (AP)

Willie Nelson will headline a rally for Democratic candidate Beto O'Rourke. (AP)

Despite clearly being in favor of the Democratic candidate, Nelson’s fans were taken aback by the news that he’s supporting a candidate whose politics they don’t agree with.

“If that’s true im done after 45 years with the Red Headed Stranger, by [sic] Willy,” one user commented on the Facebook announcement.

“Willie I have always loved you and I played your music on the local country station when I was in high school. I've always thought you were a patriot but you have jumped the shark my friend,” another user commented. “Beto O'toole aka commrade O'Rourke is a step too far. Let me know when you come back from your bad acid trip. That is all.”

“I adored you - and always have - but no more. This is more than sad - I am devastated. Did you forget you are in Texas? Dear God I will pray for you to open your eyes. IT'S NOT TOO LATE TO CANCEL THAT GIG,” another impassioned fan wrote.

“I have adored you for over 40 years, you entering politics has now ended that adoration. What a horribly disappointing decision you are making. Beto will kill this state and all the laws of our land. DONE,” wrote another.

So far, Nelson has not commented on the backlash.

It’s worth noting that some of his fans took to the comments to support the singer’s decision to headline the rally, noting that true fans were aware of his political leanings all along. However, a more vocal majority seemed surprised and against the upcoming gig.