Donald Trump and Ted Cruz avoided going after each other on the debate stage or the campaign trail – until this week. The Fix's Chris Cillizza explains why the Trump-Cruz dynamic isn't going away any time soon. (Peter Stevenson/The Washington Post)

Say what you will about Donald Trump, but the man is not stupid. Particularly when it comes to how to play the political game. Witness how he has injected the idea — that nominating Ted Cruz might be a dangerous thing for Republicans because of the fact that the Texas senator was born in Canada — into the daily narrative this week.

The idea first came up in an interview with The Washington Post published on Tuesday. Here's what Trump said:

“Republicans are going to have to ask themselves the question: ‘Do we want a candidate who could be tied up in court for two years?’ That’d be a big problem,” Trump said when asked about the topic. “It’d be a very precarious one for Republicans, because he’d be running and the courts may take a long time to make a decision. You don’t want to be running and have that kind of thing over your head.”

Trump added: “I’d hate to see something like that get in his way. But a lot of people are talking about it, and I know that even some states are looking at it very strongly, the fact that he was born in Canada and he has had a double passport.”

Then, in an interview Tuesday at Trump Tower, Trump made a similar case to Joe Scarborough and Mika Brzezinski. Here's the relevant part of that transcript:

SCARBOROUGH:  I ask you something about Ted — Ted, I — I actually, I — there’s a legal mind on the conservative side that has been saying that he has concerns that Ted Cruz may not be qualified to be president of the United States, may not meet the qualifications to be the president of —

TRUMP:  Because of where he was born.

SCARBOROUGH:  Because of where he was born. This is something obviously you talked about before with Barack Obama, it’s something that I suspect we’re going to be hearing more about in the next couple weeks. 

Is there any validity to those claims?

TRUMP:  Well, I mean, honestly I hope it’s not the case.  I hope that’s not going to be a problem for him, but I’ve been hearing a lot about it, and you’ve been hearing, and I guess everybody’s talking about it now that he’s doing better, and I think that they are looking at it.  

And it’s a problem for him, and it’s a problem obviously for the Republicans because if the — let’s assume he got a nomination and the Democrats bring suit, the suit takes two to three years to solve, so how do you run?

So, it’s certainly a concern, I guess, for the party, but I hope that’s not the case.  I’m not involved in that, but a lot of people are bringing it up, absolutely.

What Trump is doing is a nifty bit of blame-shifting. In each instance, he's ensuring that the idea that nominating Cruz could create big problems for the GOP gets out there without having to carry the burden of proving that Cruz is ineligible to run. (He's not; we've done a bunch of reporting on this.) Some people say Cruz isn't eligible to be president, Trump says. I am not sure whether they're right, but it's something to think about. All I am doing is making sure you are aware of all of the information out there — and what people are saying.

Trump knows, of course, that the very insinuation that Cruz, who has passed Trump in Iowa polling, might be a risky nominee will raise doubts for some Republicans who were moving the Texas senator's way. Trump benefits from the insinuation without having to own it in any meaningful way.

And, of course, Trump was among the first major Republican figures to suggest Cruz's citizenship might be an issue. In an interview in March 2015 with the New York City Fox affiliate, Trump offered this assessment:

"Well he’s got, you know, a hurdle that nobody else seems to have at this moment. It’s a hurdle and somebody could certainly look at it very seriously. He was born in Canada … if you know … and when we all studied our history lessons … you’re supposed to be born in this country, so I just don’t know how the courts would rule on it. But it’s an additional hurdle that he has that no one else seems to have."

So, even before Trump was running for president — he didn't announce until almost three months later — Trump was trying to inject the idea that Cruz might not be eligible to run for president into the political bloodstream, elevating a pet cause on the left to semi-credible status solely by making mention of it.

Trump's demurrals on the subject ring somewhat false. If he wanted to make Cruz's birth country a non-issue, he could answer the question the way Jeb Bush did when asked in New Hampshire on Tuesday whether he believed Cruz was a U.S. citizen. "Yeah. I do," Bush said with a laugh. "Look, yes."

Trump didn't do that. On purpose. Because he saw the chance to raise doubts about Cruz (again) while keeping his own hands relatively clean. It's yet more evidence of Trump's master manipulation of the media in this race to date.