The coming showdown between Donald Trump and Ted Cruz

​Produced by CBS from Reuters file photos of Donald Trump and Ted Cruz

This article originally appeared on Slate.

Sen. Ted Cruz and Donald Trump appear on the cusp of a more frank and open exchange of views. The two are at the top of the GOP polls, and there are new signs that the armistice that has prevailed between them may give way to something more pointed. Before this period begins, however, we should pause to note that Cruz has thus far managed the Trump relationship with considerable tactical restraint. He has a strategy and has stuck to it. Critics had once claimed he lacked this skill. It's an important one for a president to have.

Though Cruz and Trump have not attacked each other, it's obvious that they have criticisms in the drawer and prepared for use. This summer, Trump raised questions about Cruz's Canadian birth and whether he was constitutionally eligible to be president. I asked him about this last week. Would he bring that up again? "I'll only bring it up if he's a final two," said Trump.

The New York Times has audio of Cruz speaking at a recent fundraiser about Trump's lack of judgment. "People are looking for who is prepared to be a commander in chief," Cruz said in a portion of his remarks devoted to Trump and Ben Carson. "Who understands the threats we face? Who am I comfortable having their finger on the button? Now that's a question of strength, but it's also a question of judgment. And I think that is a question that is a challenging question for both of them."

Trump responded on Twitter in his trademark fashion. ".@tedcruz should not make statements behind closed doors to his bosses, he should bring them out into the open--more fun that way!" Trump tweeted Friday morning. He then added: "Looks like @tedcruz is getting ready to attack. I am leading by so much he must. I hope so, he will fall like all others. Will be easy!"

Cruz responded not with a knockout but with a nuzzle. "The Establishment's only hope: Trump & me in a cage match. Sorry to disappoint--@realdonaldtrump is terrific. #DealWithIt"

Cruz is trying to avoid a fight. He doesn't want to alienate Trump's voters, who he thinks will largely come his way eventually. (Polls show there is something to this.) He's also hoping to reframe all inevitable future conflict between the two of them as a gift to the GOP establishment. He's battling Trump to be the anti-establishment tribune, so this is both an attack and a shield. He's not going to give in to the establishment the way the Donald is by getting into a public fight. Should Trump continue to attack Cruz, the senator hopes it will be seen as a gift to the establishment.

The strategy is one Cruz articulated in that same fundraiser. "My approach, much to the frustration of media, is to bear-hug both of them and smother them with love," Cruz said. "I believe that gravity will bring both of those candidates down. I think the lion share of their supporters will come to us." Cruz will lay down like a lamb to get what's coming to the lion.

In sticking to this strategy, Cruz has demonstrated a protracted display of tactical restraint. He has relentlessly embraced Trump and avoided opportunities to attack him. Normally, Cruz is not shy about calling out apostates. He's done it on the Senate floor and at countless conservative gatherings. He's made a career of it. Were he running against Sen. Trump and not Front-Runner With Lots of Money Trump, Cruz, it's not hard to imagine, would be fileting Trump for his shifting positions on issues from taxes to abortion. (He's doing a version of that now to Sen. Marco Rubio.)

Cruz also likes to debate, and when he does, he doesn't simply speak to the beauty of his arguments alone. He also dismantles the positions and questions the motivations of his opponents.

So this is no small act of restraint. Additionally notable is that Cruz's colleagues said this restraint was the key thing that Cruz lacked in his fight against the Affordable Care Act. He had no strategy, they argued. He was an ideologue whose passions (whether they were for self-elevation or against the bill) propelled him into a foolish fight with no possibility of a successful outcome. "I didn't go to Harvard or Princeton, but I can count," said Sen. Bob Corker of Tennessee at the time. "The defunding box canyon is a tactic that will fail and weaken our position."

Were Cruz an ideologue compelled to speak out against wrongs of the kind he has identified in the Senate, he would have spoken out already quite a lot about Trump. But Cruz knows the difference between a losing fight where he gains greater glory among the voters he wants, like the Affordable Care Act shutdown fight, and a fight that might threaten his relationship with those very voters.

During the Affordable Care Act debate, when Cruz's opponents called for tactical restraint, he framed their position as an ideological weakness. He faces no real risk of one of his opponents making a similar argument against him now. Because making the equivalent argument about Trump that Cruz made about the ACA would mean arguing that tolerating Trump is a betrayal of deeply held conservative beliefs. No candidate is remotely ready to go that far yet.

Cruz is demonstrating a skill a president must have: avoiding a confrontation for a larger goal. During political campaigns, there is an obsession with presidential action. The party out of power demands that the president do something in response to everything. But it's often the case that letting a situation develop is the wiser course. That's the course Cruz is on.