Pence endorses Robson, pitting him against Trump in Arizona's governor's race

Former Vice President Mike Pence endorsed Karrin Taylor Robson in the GOP primary for governor, aligning himself with Gov. Doug Ducey and against former President Trump.

• Trump has endorsed Kari Lake.

Driving the news: Pence and Trump will both be in Arizona on Friday to promote their candidates in the governor's race, which has increasingly become a proxy war between the former president and his rivals within the Republican Party.

• Pence will appear with Robson at campaign events in Phoenix and southern Arizona.
• Trump will hold a rally in Prescott Valley, where he'll be joined by Lake and other candidates he's endorsed.
• The Trump rally was originally planned for last Saturday but was rescheduled after the death of his former wife, Ivana.

What he's saying: "As Arizona Democrats pursue the reckless Biden-Harris agenda, Karrin Taylor Robson is the only candidate for governor that will keep Arizona’s border secure and streets safe, empower parents and create great schools and promote conservative values," Pence said in a press release issued by Robson's campaign.

The other side: In a statement to Axios Phoenix, the Lake campaign thanked Pence "for clearly reminding Arizonans that the choice in this race is between President Trump, Kari Lake and the America First movement versus Robson, Ducey and the Arizona Swamp."

Meanwhile: Ducey and Trump have also endorsed rival candidates in the Republican primary for secretary of state.

Flashback: Ducey famously ignored Trump's phone call when the then-president sought to pressure him to not certify election results in Arizona, which President Biden won by 10,457 votes.

• Trump has repeatedly lashed out at him since then.

Ducey has taken on a more active role in stumping for Robson, appearing on CNN's State of the Union on Sunday to tout her conservative credentials and to criticize Lake.

• He said Robson is "the real conservative" who is pro-gun, pro-life and a successful businessperson.

The intrigue: Ducey is also the head of the Republican Governors Association (RGA), which is tasked with helping GOP candidates in gubernatorial races around the country.

• Asked by host Dana Bash whether the RGA will assist Lake if she's the nominee, he said, "All post-Aug. 2 roles are to be determined."

Yes, but: Ducey added that the RGA is in the business of electing Republican governors, telling Bash, "We protect our incumbents. We keep our red states red."

• The RGA has already reserved $10.6 million in TV airtime for the general election in Arizona.