The Club for Growth is taking sides in the GOP Senate primary in Nebraska, where a competitive nomination battle has unfolded for a safely Republican seat.

On Thursday, the club’s political action arm announced its endorsement of Midland University President Ben Sasse, one of a handful of Republicans running for the state’s open seat. In a statement, Club for Growth President Chris Chocola highlighted Sasse’s outspoken opposition to President Barack Obama’s health care law, which stems from Sasse’s experience as an assistant secretary at Health and Human Services.

“Ben Sasse is the rare candidate who can clearly and forcefully prosecute the case against ObamaCare, not only because it’s an unconstitutional assault on our liberty, but also because he’s read every word of it,” Chocola said.

Sasse was previously endorsed by Senate Conservatives Fund. Both groups have endorsed in other Senate races,

by Senate Conservatives Fund. Both groups have endorsed in other Senate races, including the challenger to Sen. Thad Cochran, R-Miss.

Other primary contenders include former state Treasurer Shane Osborn, bank president Sid Dinsdale and attorney Bart McLeay. They are running for the seat of retiring GOP Sen. Mike Johanns.

The race is rated Safe Republican by Rothenberg Political Report/Roll Call.