For those of you who missed it, Senators Marco Rubio and Rand Paul have been going back and forth for the last week, arguing with each other on Twitter ever since President Obama announced that he was going to be re-establishing relations with Cuba.

From TPM last week: Rand Paul Slams Marco Rubio Over Cuba As Feud Escalates:

The disagreement between Sens. Marco Rubio (R-FL) and Rand Paul (R-KY) over America's changing relationship with Cuba is escalating quickly.

Rubio was among the loudest opponents to President Barack Obama's announcement that the United States would begin normalizing relations with its Caribbean neighbor. After Paul said he supported the change, Rubio lashed out, saying Paul "has no idea what he's talking about."

Both are considered potential 2016 presidential contenders, and Paul struck back on Friday on both Twitter and Facebook.

As they noted, Paul also went after Rubio on his Facebook page here.

This Sunday, the feud continued with Rubio attacking Paul as wanting to become the "chief cheerleader of Obama's foreign policy" on ABC's This Week with George Stephanopoulos.

STEPHANOPOULOS: I want to get to the debate between you and Rand Paul inside the Republican Party right now.

You guys got in something of a Twitter war over the course of this week on this issue of Cuba. The latest one from Rand Paul saying, "Senator Marco Rubio is acting like an isolationist who wants to retreat to our borders and perhaps build a moat. I reject this isolationism. This seems to be a preview of the debate of 2016."

RUBIO: Well, first of all, Rand, if he wants to become the chief cheerleader of Obama's foreign policy, he certainly has a right to do that.

I'm going to continue to oppose the Obama -- Obama-Paul foreign policy on Cuba because I know it won't lead to freedom and liberty for the Cuban people, which is my sole interest here.

STEPHANOPOULOS: He's running hard for the nomination.

If he gets it, could you support Rand Paul and his foreign policy, if he were the Republican nominee?

RUBIO: Well, I anticipate -- I anticipate supporting whoever the Republican nominee is and I'm pretty confident that the Republican nominee for president will be someone who has a pretty forceful role -- view of America's role in the world as a defender of democracy and of freedom and also understands that it's important for America to be engaged on the global stage.