TYLER COWEN: The Right Finds the Perfect Weapon Against the Left: Conservatives are using identity politics to destroy liberalism from within.

Imagine the perfect political and intellectual weapon. It would disable your adversaries by preoccupying them with their own vanities and squabbles, a bit like a drug so good that users focus on the high and stop everything else they are doing.

Such a weapon exists: It is called political correctness. But it is not a weapon against white men or conservatives, as is frequently alleged; rather, it is a weapon against the American left. To put it simply, the American left has been hacked, and it is now running in a circle of its own choosing, rather than focusing on electoral victories or policy effectiveness. Too many segments of the Democratic Party are self-righteously talking about identity politics, and they are letting other priorities slip.

Of course there is a lot of racism out there, which makes political correctness all the more tempting. Yet polling data suggests that up to 80 percent of Americans are opposed to politically correct thinking in its current manifestations. Latinos and Asian-Americans are among the groups most opposed, and even 61 percent of self-professed liberals do not like political correctness.

The PC weapon reared its head again this week when Senator Elizabeth Warren made a big show of her genealogical test showing she is some small part Native American. To someone immersed in the political correctness debates, this obsession with identity might seem entirely natural. But the actual reality is more brutal.

The reality is that many Americans already think that the Democrats talk too much about identity.

Well, that’s because they do.