The public battle between San Antonio Mayor Julian Castro and State Sen. Dan Patrick (R-Houston) is escalating, and Patrick is now using the feud in his race for Lieutenant Governor, 1200 WOAI news reports.

  "I was blind sided," Patrick told 1200 WOAI's Chris Fox.  "He accused me of being the most anti immigrant candidate running for statewide office."

  The race for Lieutenant Governor has become a rush to the right, as all four candidates for the Republican nomination vie to prove their conservative credentials, especially after incumbent David Dewhurst was blitzed by Ted Cruz during Dewhurst's attempt to win election to the U.S. Senate in 2012.

  But Castro took exception to Patrick's anti immigration rhetoric, including comments like "they threaten your family, they threaten your life, they threaten this state!"

  Castro says he didn't like what he heard, and said so in a Tweet.

  "I will stand up to that kind of rhetoric," Castro told 1200 WOAI.  "Its wrong and I don't like it.  Dan Patrick is scapegoating immigrants and using fear as a way to win votes and get elected Lieutenant Governor."

  It then progressed to Patrick challenging Castro to debate the immigration issue.

  "I'll debate him any where any time," Patrick said.

  Castro said he will not be available for a debate 'until March,' which, inconveniently for Castro, will be after the March 4th primary.

  But that is not stopping Patrick from using the issue in one of his new radio ads.

  "Castro and his pal Obama know that I will do what our current Lieutenant Governor won't do," Patrick says in a new ad.  "I'll secure the border."

  In another Patrick ad, an announcer plays up the rift between the two.

  "Julian Castro and Barack Obama know that Dan Patrick is the most conservative candidate for Lieutenant Governor, who will secure our border.