Jonathan is right, Marco Rubio is far more prepared for the VP slot than Sarah Palin in 2008. Case in point: he delivered an impressive speech on foreign policy earlier today at the Brookings Institute. He even lost the last page of his remarks (every speaker’s nightmare) but managed to take it in stride.

The full text of the speech is worth reading here, but his direct repudiation of the isolationist streak within his own party is drawing the most attention:

I am always cautious about generalizations but until very recently, the general perception was that American conservatism believed in a robust and muscular foreign policy. That was certainly the hallmark of the foreign policy of President Reagan, and both President Bush’s. But when I arrived in the Senate last year I found that some of the traditional sides in the foreign policy debate had shifted.

On the one hand, I found liberal Democrats and conservative Republicans working together to advocate our withdrawal from Afghanistan, and staying out of Libya. On the other hand, I found myself partnering with Democrats like Bob Menendez and Bob Casey on a more forceful foreign policy. In fact, resolutions that I co-authored with Senator Casey condemning Assad and with Senator Menendez condemning fraudulent elections in Nicaragua were held up by Republicans. I recently joked that today, in the U.S. Senate, on foreign policy, if you go far enough to the right, you wind up on the left.

The far-left and far-right don’t just agree on the embrace of American decline, but also on the other problematic attitudes that tend to go along with isolationism and non-interventionism, including antipathy toward Israel and indifference to human rights in other countries. As a young senator elected with Tea Party support, Rubio is in a prime position to rebut creeping isolationism/non-interventionism among the conservative grassroots.

Rubio gave a broad outline of his vision for U.S. foreign policy, which is heavily influenced by Robert Kagan’s arguments on the myth of American decline (Kagan has also advised Romney on foreign policy). Rubio spoke passionately about human rights and called the spread of political and economic freedom across the world “a vital interest” for the U.S. He acknowledged that working in coalitions with other countries is often helpful, but added that these coalitions are most successful when the U.S. takes the lead. And he argued that if military action needs to be used against Iran, then Israel shouldn’t be left to shoulder the burden on its own.

Still, this is a speech that Rubio could have delayed for a few months. The fact that he decided to give it today, at the height of speculation over his possible VP nod, seems to indicate that he’s either interested in the job, or just wants to give the impression that he is.