When former senator Joe Lieberman (I-Conn.) was asked why he remained a Democrat, despite his sharp differences with his party over foreign policy, he would often answer that he wished to bring back the “Scoop Jackson” wing of the Democratic Party — that is, domestic liberalism coupled with a robust, internationalist foreign policy.  (This was a senator who championed both the elimination of “don’t ask don’t tell” and the Iraq surge.) He would cite the foreign-policy tradition running from Harry S Truman to John F. Kennedy to Bill Clinton, explaining why support for a strong U.S. military, a staunch defense of human rights and close alliances with democratic friends are in America’s interest. In fact, sadly, Lieberman proved to be the Scoop Jackson wing.

Now, however, that a Democratic president has assumed executive power to use drones against terrorists, encounters an ongoing threat from Iran (as James Traub observes, “There is no evidence that the sanctions will bring Iran to its knees and force the supreme leader, Ayatollah Ali Khamenei, to accept the humiliation of abandoning his nuclear program.”) and faces defense sequester, you have to wonder whether another independent-minded Democrat is out there to rebut the left’s anti-defense and anti-anti-Iran notions and defend the president’s war powers.

Leon Panetta at CIA and then the Pentagon mostly fell into that mold, but he’s retiring to California. Another California Democrat, Howard Berman, lost his House seat in 2012. Sen. Chuck Schumer (D-N.Y.) crossed himself off the list of serious foreign-policy makers when he made a fool of himself in shilling for the hapless Chuck Hagel. And Sen. Robert Menendez (D-N.J.), who played a key role in crafting Iran sanctions legislation, is in the process of self-immolation. Is there anyone left?

Ben Cardin Sen. Ben Cardin (Pete Marovich / Getty Images)

The most likely candidate, I would suggest, is Sen. Ben Cardin (Md.). He is one Democrat who has not yet made a fool of himself in the Hagel proceedings. He was the key player in the landmark Magnitsky legislation (where he bucked the administration) imposing a visa ban on Russian officials who participate in human rights abuses. He is in as safe a seat as any Democrat can have these days and can easily adopt a more maverick profile without endangering his political future one iota. If Menendez’s problems do overwhelm him, Cardin stands to take over the Senate Foreign Relations Committee chairmanship, from which he would be in an ideal spot to influence foreign policy.

In the current Senate, which votes very little on actual legislation and hasn’t managed to get out a budget in years, it is not easy to rise above the fray. But foreign policy is certainly one area in which congressional oversight, confirmation hearings and the bully pulpit afford an opportunity to make a name for yourself and leave a lasting legacy. That, almost by definition, requires pushing back against the president (whose foreign policy is incoherent, at best) on issues like Syria, Iran and human rights around the world.

It may be that no Democrat is inclined to or willing to fill the role of principled advocate for a strong international presence in the tradition of Truman, Kennedy and Clinton. If so, it is a loss to the country and the Senate. But maybe Cardin will stand out from the crowd. Now is a good time for a Democrat to get serious about national security, and to inherit the mantle of Scoop Jackson.