Vice President Joe Biden may still ultimately stay out of the race for president. But on Tuesday night, he made clear he doesn’t mind making Hillary Rodham Clinton uncomfortable in the process.

For the third time in less than 36 hours, Biden took a veiled shot at Clinton for including Republicans on her list of "enemies" during last week’s Democratic debate in Las Vegas. And what Biden first said almost in passing was, by its third utterance, unmistakable.

"It is possible, it is necessary, to end this notion, to end this notion that the enemy is the other party. End this notion that it is naive to think we can speak well of the other party and cooperate," Biden said at a dinner honoring former Vice President Walter Mondale.

"What is naive," he continued, "is to think it is remotely possible to govern this country unless we can. That is what is naive."

In implicitly criticizing Clinton, and more explicitly the dysfunction in Washington, Biden seemed to be following the Obama campaign’s 2008 playbook against her, when the soon-to-be president vowed to put a generation of partisan animosity behind him.

"One of the reasons why it's so hard to govern today is that it's almost impossible, ladies and gentlemen, to reach consensus if you accuse someone else of being unethical, or in someone's pocket," Biden said.

Acknowledging Mondale and former President Jimmy Carter, both in the audience, he said: "The lesson I learned from both of you is how can you govern this incredibly diverse democracy without arriving at consensus. It's simply not possible."

"It's mostly important that everyone in this room understand the other team is not the enemy. If you treat it as the enemy, there is no way you can ever, ever, ever resolve the problems we have," Biden said in concluding his remarks.

Biden has faced increasing pressure from senior Clinton figures to make a final decision about whether to run for president, one he appears unlikely to make for at least another day. Biden's comments Tuesday could have been a signal that he is indeed leaning toward entering that race, or simply a warning to Clinton's team to ease off the pressure.