Some Arizona Republican voters received a mailer in recent days from a political action committee that highlights Republican presidential candidate Donald Trump’s endorsement of Senator John McCain for re-election.

McCain is facing Kelli Ward in the August 30 Republican primary.

“Our conservative Republican team agrees, re-elect John McCain!” reads the mailer, along with photos of Trump, running mate Gov. Mike Pence and Arizona Gov. Doug Ducey and quotes of their endorsements of McCain.

But other Republican voters received a different version of the same mailer that left off any reference to Trump and Pence. There was still a conservative Republican team, but this time it included 2012 Republican presidential candidate Mitt Romney and Senator Jeff Flake along with Ducey.

Both Romney and Flake have been outspoken critics of Trump.

The mailer was not sent by the McCain campaign, but by Citizens for a Working America, a political action committee. Such organizations are not supposed to coordinate directly with candidates.

KJZZ spoke with a handful of voters who received one of the mailers. The voters who received the Trump and Pence version lived in Paradise Valley and Fountain Hills, while the voters who received the version with Romney and Flake lived in Mesa and Gilbert.

The sample size is too small to draw any definitive conclusions, but the Romney/Flake version may have been an effort to target areas with a large number of Mormon voters, since Trump has polled less favorably with that group. Both Romney and Flake are also members of the Church of Latter Day Saints.

Trump’s candidacy has been a major point of tension in McCain’s re-election run.

Last year Trump seemed to mock McCain for being a prisoner of war. ““He’s not a war hero,” Trump said then. “He was a war hero because he was captured. I like people who weren’t captured.”

As recently as the beginning of August, Trump threatened to withhold his endorsement of McCain, but ultimately came around a few days later.

McCain has maintained he will support the nominee but has kept a distance from Trump and did not attend the Republican National Convention in Cleveland.

Meanwhile Democratic congresswoman Ann Kirkpatrick has attacked McCain for continuing to endorse Trump. At the same time, primary challenger Ward has criticized McCain for not supporting Trump enough.

Citizens for a Working America PAC did not return a request to comment.