Yes. The point is to say something that eats up each news cycle.
Trump says: Ted Cruz can't be POTUS because he's Canadian. The media spends a week talking about it.
Trump says: Ted Cruz cheated in Iowa. The media will spend until Saturday talking about it.
At the NH debate, Trump will accuse Cruz of something else. The media will spend its time on that accusation.
If there is a lull in the coverage, Trump will say something about Megyn Kelly or some other "journalist" so the media can focus on that instead.
The common theme is the media talks about Trump for free while repeating the nasty accusation regardless of the merits.
I hope that's all this is. Trump is my candidate. I think Cruz will be weak in the general election, even against Hillary. But if Trump really tries to sue Cruz or persists in demanding another caucus, both futile gestures, he's going to look both weak and unhinged, a deadly combo in politics.
If he is serious he's making a rookie error. Taking a tactic that can work in business negotiations - threatening or even filing lots of trivial lawsuits to put the other side off balance and intimidate them - and trying it in the public world of politics where the more litigious side often loses the PR battle even if they prevail in court.
And in this case it's clear that Trump will not prevail in either arena.
Trump is like the child who cried wolf; no one is listening anymore.