So it's come to this: A real life measuring contest at a Republican presidential debate.

After Fox News host Bret Baier invoked Florida Sen. Marco Rubio’s escalating personal attacks of Donald Trump, Rubio said the billionaire deserves the criticism because he’s “mocked everyone and has done so to people on this stage.”

“If there’s anyone who deserved to be attacked, it’s Donald Trump,” he added.

Trump then summoned up Rubio’s criticism of his hands.

“Look at those hands. Are they small hands?” he asked.

“And, he referred to my hands. If they’re small, something else must be small,” he said, a not so subtle reference to his genitals. “I guarantee you there’s no problem, I guarantee you.”

We never thought we'd be writing about this, either.