As other Republican presidential candidates go after Donald Trump, Texas Sen. Ted Cruz is getting cozy with him. The two men are in a so-far cordial competition for many of the same anti-establishment conservatives, and they’re about to share a stage.

On Wednesday, at Cruz’s invitation, Trump is to appear with him at a Capitol Hill rally protesting the proposed nuclear agreement with Iran.

One of 16 GOP candidates looking up at Trump in the polls, Cruz says the invitation was only to attract more attention to objections to the “catastrophic” deal. “Wherever Donald goes, the media follow in droves,” Cruz told The Associated Press. Any suggestion that the joint appearance has deeper meaning would be a “political horse game,” he said.

Yet Cruz , the tea party hero who helped shut the federal government in 2013, needs the same frustrated voters who have pushed Trump to a surprising lead five months before primary voting begins. If it takes a shared stage to convince those conservatives that he should be their choice, so be it.

Cruz has stood out for his refusal to criticize Trump. Among other presidential contenders, Rick Perry called Trump a “cancer” on conservatism, Rand Paul has called attention to the billionaire’s friendship with Democrats Hillary and Bill Clinton, and Jeb Bush has branded Trump’s rhetoric on immigration “ugly” and “divisive.”

“An awful lot of presidential candidates,” Cruz said, “have gone out of their way to take a stick to Donald Trump.”

“I am not one of them.”

Instead, he credits Trump with “shining a light” on an immigration crisis and getting conservatives excited.

“Look, I like Donald Trump, and I am glad Donald Trump is in this election,” he said at a recent stop in South Carolina.

Yet he said: “There will come a time as this campaign goes forward for additional policy differences and differentiation.” And his standard campaign pitch — which he has not changed through Trump’s rise — contains the seeds of what could emerge as an argument against Trump when the time for comity passes.

In every speech and almost every interview, Cruz hammers “the Washington cartel.” His definition: “Anyone who stands with the career politicians in both parties” and gets “in bed with the lobbyists and the special interests.” That’s how the establishment operates, Cruz says.

Trump admits that he has played by those rules, explaining his history of campaign contributions across the political spectrum this way: “When you give, they do whatever the hell you want them to do.”

Cruz praises Trump for his focus on immigration, though suggests he was there first, back when all his rivals “supported amnesty.”

“Illegal immigration has been an issue I have been leading the fight on for many years,” he says.

Trump has shifted his positions over the years and has supported ways of granting legal status to people who are in the U.S. illegally. Even now, his call to deport everyone who is in the U.S. illegally but let “the good ones” return quickly is considered a form of amnesty by some conservatives — not to mention impractical in the eyes of many.

And the core of Cruz’s argument is that he’s a “consistent conservative day in and day out.”

“With me, you know what you’re gonna get,” he says.

Trump has never held office, so he’s not one of Cruz’s standard targets: the “campaign conservatives” who “say one thing and then do another.” But he’s certainly flip-flopped.

He now echoes the Republican call to repeal President Barack Obama’s health care law, but once advocated a single-payer health care system, an even farther reaching overhaul that Cruz assails as “wild-eyed socialism.”

Earlier in his business career, Trump endorsed income tax increases for top earners like himself. Cruz , though he has not released his tax plan, delights his crowds with visions of abolishing the Internal Revenue Service.

Trump also shifted his position on abortion rights, which he once supported, while Cruz has consistently opposed them and vows a Justice Department investigation of Planned Parenthood, the women’s health organization that provides abortion services, on his first day in office.

While both men have drawn support from evangelical Christians, it is Cruz who sprinkles his pitch with Scripture and talks about his father “traveling the country to preach the Gospel.”

At least for now, however, Cruz seems content to let voters pick up on the distinctions themselves.

“Every one of us,” he tells them, “should ask any candidate who shows up in front of us, ‘You say you believe these principles. Prove it. When have you stood up and fought for it? When have you bled for it? And what have you accomplished?’ As the Scriptures say, you shall know them by their fruits.”