There are two kinds of Washington fights, the theatrical and the genuine.

In a theatrical fight, both sides go through the motions. They may look like they are really fighting, but it's really just a charade designed to communicate to constituents and interest groups. The final outcome is preordained.

In a genuine fight, the outcome is actually uncertain, and the combatants are really annoyed, not just pretending. That kind of fight creates real winners, real losers, and, sometimes, lasting rifts and scars.

The fight under way right now about trade between Elizabeth Warren and Barack Obama is starting to look more and more like a genuine fight.

President Obama got testy in a recent interview with Yahoo! News, calling Senator Warren "absolutely wrong" and noting, "The truth of the matter is that Elizabeth is, you know, a politician like everybody else."

The Yahoo! News reporter, Matt Bai, said Obama "seemed unusually irritated." Bai wrote, "like a marriage in which the spouses pretend to be happier than they really are, Obama's polite alliance with the populist left appears to be suddenly crumbling under the weight of free trade."

Senator Warren, for her part, responded by accusing Obama of trying to pass a secret deal. She told The Washington Post: "the president won't actually let people read the agreement for themselves. It's classified." And in a move that can't have pleased President Obama, she not-so-subtly suggested that Hillary Clinton—his one-time-rival and would-be-successor—has a firmer grasp of the matter: "Hillary Clinton in her book raised concerns about precisely this issue."

As Obama himself observed, part of the reason this is so raw for the left and labor is that they still haven't gotten over Bill Clinton and Al Gore's support, more than 20 years ago, of the North America Free Trade Agreement. If Obama succeeds in getting fast-track authorization from Congress for the Trans-Pacific Partnership, and then succeeds in getting a deal passed, it could be a similarly significant achievement.

If Obama is looking for a Democratic precedent on the trade issue, he needn't stop with Bill Clinton or Al Gore. He could go back to John F. Kennedy, who made trade expansion his top legislative priority in 1962, annoying liberals like Arthur Schlesinger Jr. (who called the trade initiative "mistaken" and "overrated.") As Kennedy wrote in a January 25, 1962, Special Message to the Congress on Foreign Trade Policy, "The American consumer benefits most of all from an increase in foreign trade. Imports give him a wider choice of products at competitive prices." Kennedy went on, "the warnings against increased imports based upon the lower level of wages paid in other countries are not telling the whole story."

And Kennedy concluded, "This philosophy of the free market—the wider economic choice for men and nations—is as old as freedom itself. It is not a partisan philosophy. For many years our trade legislation has enjoyed bi-partisan backing from those members of both parties who recognized how essential trade is to our basic security abroad and our economic health at home."

Alas, while being in favor of a free market on trade is bipartisan, so is being against it; a Wall Street Journal editorial points out that Senator Warren, a Democrat of Massachusetts, is joined by Senator Sessions, a Republican of Alabama, in opposing the fast-track trade promotion authority for the president.

Give President Obama credit for taking on Senator Warren rhetorically in favor of free trade. But what about in Congress itself? Will Obama cut deals with individual legislators or twist arms to win their support for fast-track or the Trans-Pacific Partnership the same way he bought support for ObamaCare? With luck, that won't be necessary. If it is necessary, though, then we'll get a chance to see for sure whether this Washington fight is merely theatrical or really genuine. Fortunately, it comes close enough to the 2016 presidential election that contenders for that job will need to choose sides, too.