Texas Rep. Briscoe Cain and Beto O'Rourke spar on Twitter

A moment during the Houston Democratic Debate has turned to a war of words on Twitter after Beto O'Rourke says a Texas state lawmaker 'threatened' him, after his pledge to confiscate certain weapons.

O'Rourke's 'Hell yes, we're going to take your AR-15' pledge was in response to several mass-shootings in Texas over the last few years.

But when the O'Rourke campaign followed with a tweet repeating the comment, Deer Park Republican Briscoe Cain responded with his own comment:

"My AR is ready for you Robert Francis", using O'Rourke's given name.

O'Rourke followed-up:

"This is a death threat, Representative. Clearly, you shouldn't own an AR-15, and neither should anyone else."

Cain insists he didn't threaten anyone, "Beto absolutely knows that's not true, at all."

Instead, he says he was drawing from the state's unofficial motto, from the Texas Revolution, "Come and Take It".

"The real concern should be with candidates for President discussing the violation of constitutional rights," says Cain, "Had he said 'I'm going to silence you, and take away your free speech', we'd all be upset. He's doing the same thing there."    

FOX 26 Senior legal analyst Chris Tritico thinks the standoff appears more political theater, than anything else.

While the O'Rourke campaign says it filed a complaint about Cain's comments, with the FBI, Cain says he hasn't heard from the feds and the agency doesn't confirm or deny any inquiries.

In a statement, the FBI says such allegations are reviewed and appropriate action is taken, when appropriate.

"I am going to kill you' is a direct threat and you have to be in a position to do it," says Tritico, "When you say it over the Twittersphere, and you're not around each other and you don't have the ability to carry it out, it's really not a death threat."

Either way, the episode to generating a lot of attention that may not be all bad for either side.

The O'Rourke campaign is now selling t-shirts emblazoned with his pledge to confiscate weapons.

The Texas Republican Party has introduced its own t-shirts, that read: "Beto, Come and Take It".