Sen. Ted CruzRafael (Ted) Edward CruzWith religious liberty memo, Trump made America free to be faithful again Interstate compacts aren't the right way to fix occupational licensing laws Texas Dem: ‘I don’t know what to believe’ about what Trump wants for wall MORE's (R-Texas) dad is backing the Tea Party challenger running against Rep. Pete SessionsPeter Anderson SessionsAfghanistan moves reignite war authorization debate GOP angst over midterms grows Gold Star father attacked by Trump steps up role in Dem primaries MORE (R-Texas).

Rafael Cruz, a conservative activist and pastor, endorsed Tea Party activist Katrina Pierson (R) over Sessions at a Monday fundraiser.

"She's a strict constitutionalist. She's a strong conservative, and she wants to do what's right," Cruz said at a Pierson fundraiser in Dallas, according to the Dallas Morning News.

Pierson was an early backer of the younger Cruz's come-from-behind Senate primary win. Her fundraiser also featured conservative pundit Michelle Malkin, a sign she might be able to gain traction with the online community of Tea Party activists that often help fund right-wing congressional challenges.

The senator has not weighed in on the race and has not gotten involved in other primaries this election cycle. He's said he'll stay neutral in Senate primaries, though he hasn't explicitly made the same promise about House battles.

Sessions, the chairman of the Rules Committee and former chairman of the National Republican Congressional Committee, is in his ninth term.