Sen. Ted Cruz (Jim Lo Scalzo/EPA)

Sen. Ted Cruz (R-Tex.), a rising conservative kingmaker, is wading into Nebraska’s gubernatorial race, issuing an endorsement Tuesday of businessman Pete Ricketts.

“Pete Ricketts is a friend and will make an outstanding Governor. I’m proud to endorse him,” Cruz said in a statement. "I appreciate Pete’s opposition to amnesty and support for the rule of law.”

Ricketts, a 49-year-old businessman, is the son of J. Joseph Ricketts, the founder of TD Ameritrade and owner of the Chicago Cubs. He was previously the Nebraska GOP’s 2006 Senate nominee, losing that contest to Sen. Ben Nelson, a Democrat. He has since directed the Platte Institute for Economic Research, a free-market think tank in Omaha.

In recent years, the elder Ricketts has been politically active, spending millions on anti-earmark efforts and on campaigns through Ending Spending, his super PAC. According to the Omaha World-Herald, the Ricketts family has poured in $1.5 million into Pete’s coffers.

In 2012, when Cruz was running in a competitive GOP Senate primary, Ricketts’s super PAC backed Cruz, airing radio ads touting him as a conservative leader.

“Senator Cruz has been a steadfast opponent of federal government overreach on matters best left to states and local government,” Pete Ricketts said in a statement. “He's made the case and led the charge against massive top-down federal programs such as Obamacare. I am grateful to have his support.”

Nebraska’s GOP gubernatorial primary will be held on May 13. In this red state, Ricketts faces stiff competition. The crowded GOP primary includes state attorney general Jon Bruning, state auditor Mike Foley, and state senator Beau McCoy, among others.

Earlier this month, Ricketts received an endorsement from another conservative favorite: former Alaska governor Sarah Palin. Palin has also endorsed Ben Sasse, a Republican running for Nebraska’s open Senate seat.

A Cruz adviser said this is one of several endorsements the senator plans to make this spring as he looks to support tea-party allies in primaries. Last week, Cruz endorsed former Oklahoma state House speaker T.W. Shannon, who is running for Senate against Rep. James Lankford (R-Okla.), a member of the House Republican leadership.