Donald Trump just threatened to sue Ted Cruz over his Canadian birth

Donald Trump declared on Monday that he will file a lawsuit over Ted Cruz's eligibility for the White House if his Republican presidential rival does not remove television ads against him.

Taking the largely discredited line that Cruz's Canadian birth disqualifies him from the American presidency, Trump said that "Cruz has become unhinged and is lying" about Trump's record on abortion and gun rights, among other issues.

"One of the ways I can fight back is to bring a lawsuit against him relative to the fact that he was born in Canada and therefore cannot be president," Trump said. "If he doesn’t take down his false ads and retract his lies, I will do so immediately."

Cruz responded on Twitter on Monday afternoon:

You cannot simply scream "liar" when someone points out your actual positions: https://t.co/DI5HnSln62

— Ted Cruz (@tedcruz) February 15, 2016

Fellow Republican presidential candidate Marco Rubio launched a similar attack on Cruz Monday, blasting out an email titled, "Cruz BusTED On Lies."

"Senator Cruz will say or do anything to win an election including employing underhanded tactics and making charges against all his opponents that he knows are outright lies. America can’t afford more politicians like Ted Cruz who will easily sacrifice principle for political gain," said Joe Pounder, a Rubio spokesperson, in the email.

This comes after South Carolina TV stations pulled ads from a pro-Cruz Super PAC after a legal review. The ad attacked Rubio's immigration record and alleged the Florida senator's support for "sanctuary cities."

But though Trump and Rubio are joining forces in ganging up on Cruz, questioning the Americanness of others has been a staple of Trump's presidential campaign — be it over Mexican immigrants, Muslims, or his fellow presidential contenders.

Trump's threat to sue Cruz over his presidential eligibility is a purely retaliatory gesture over the ads, which appear to be an unrelated issue. There are broad First Amendment protections for speech about public figures, and it's unlikely Trump could win a case against Cruz in court.

It should also be noted that this is unlikely to prove an effective deterrent for Cruz's campaign, given that Trump's supporters have already filed a lawsuit over Cruz's eligibility, according to the Hill.

In his statement, Trump also called on the Republican National Committee to do something to stop Cruz's attack ads.

"Additionally, the RNC should intervene, and if they don’t they are in default of their pledge to me," Trump said.

Trump signed a pledge not to launch an independent third-party bid for the White House if he lost the Republican nomination, but that was contingent on the RNC acting fairly to him. How to act fairly by Trump's standards, however, was left undefined.

Will you support Vox’s explanatory journalism?

Most news outlets make their money through advertising or subscriptions. But when it comes to what we’re trying to do at Vox, there are a couple of big issues with relying on ads and subscriptions to keep the lights on:

First, advertising dollars go up and down with the economy. We often only know a few months out what our advertising revenue will be, which makes it hard to plan ahead.

Second, we’re not in the subscriptions business. Vox is here to help everyone understand the complex issues shaping the world — not just the people who can afford to pay for a subscription. We believe that’s an important part of building a more equal society. And we can’t do that if we have a paywall.

So even though advertising is still our biggest source of revenue, we also seek grants and reader support. (And no matter how our work is funded, we have strict guidelines on editorial independence.)

If you also believe that everyone deserves access to trusted high-quality information, will you make a gift to Vox today? Any amount helps.

One-Time Monthly Annual

$5/month

$10/month

$25/month

$50/month

Other

$

Yes, I'll give $5/month

Yes, I'll give $5/month

We accept credit card, Apple Pay, and Google Pay. You can also contribute via