Rand Paul vs. Hillary Clinton: A preview of 2016?

Hillary Clinton's assured and assertive appearance before the Senate Foreign Relations Committee has only increased speculation about a possible Clinton presidential run in 2016.

But the hearing has also given an unexpected jolt of publicity to another possible 2016 contender: Kentucky Sen. Rand Paul (R).

Senator Paul, of course, had one of the most biting – and most replayed – exchanges with Secretary Clinton, telling her at one point: "I'm glad that you're accepting responsibility. I think that ultimately with your leaving, you accept the culpability for the worst tragedy since 9/11. And I really mean that. Had I been president at the time, and I found that you did not read the cables from Benghazi, you did not read the cables from Ambassador Stevens, I would have relieved you of your post. I think it's inexcusable."

It was an eyebrow-raising moment, not only because Paul had the audacity to criticize Clinton so sharply to her face, but because he actually referred to himself, hypothetically, as the president. This is something senators are not typically in the habit of doing – at least, not in public (sample headline from The Atlantic Wire: "In Rand Paul's Imaginary Presidency, He Would Have Fired Clinton").

Paul's attack was so lacking in typical Senate deference that The Washington Post's Dana Millbank described an unnamed Clinton aide as unable to hold back a shocked, "Ohhh!" Mr. Millbank then wrote: "But Paul, a man of exotic opinions, is never going to be president, and Clinton deflected his provocation with a mild reply: 'I believe in taking responsibility, and I have done so.' ”

It's true that Paul – the son of offbeat former presidential candidate and recently retired Rep. Ron Paul (R) of Texas – would be a dark horse when it comes to 2016, and dark horses rarely wind up winning (just ask his father). As one measure of just how uphill the climb would be, a December poll taken by Public Policy Polling found Clinton beating Paul by 5 points in a hypothetical matchup in his own redder-than-red home state of Kentucky. 

But after Wednesday's performance, one conclusion seems inescapable: Paul certainly appears to be eyeing a run. And as one of the most unpredictable, attention-getting forces to hit the Senate in some time, it's impossible to know how Paul might shake up the race.

A former ophthamologist turned tea party favorite, he's quickly established himself as a politically potent blend of his father's independent libertarianism and more typical establishment Republican positioning. In recent weeks, he has voted "no" on the fiscal cliff deal, taken a prominent trip to Israel, and vowed to "nullify" President Obama's executive actions on guns. He missed the inaugural festivities to attend a meeting of conservatives in the key primary state of South Carolina, and was recently announced as a featured speaker at the upcoming Conservative Political Action Conference in Washington.

As Oxford historian Timothy Stanley recently wrote on CNN.com, "Ever since the last presidential election, Rand Paul hasn't set a foot wrong." 

Does that mean Paul could actually succeed in wresting the nomination away from, say, Florida Sen. Marco Rubio (R), another rising-star senator with tea party roots, whose relatively mild questioning of Clinton yesterday drew everything from yawns to charges of neophytism?

At this point, we wouldn't bet on it. But he could definitely make things interesting.