It may not always get the presidential nominees it wants, but it’s moving the party its way on policy. My column uses the Biden campaign to illustrate the point.

Even if Joe Biden wins the presidential primaries, as now looks likely, he will be running on a more progressive platform than previous Democratic nominees.

It’s a platform more progressive than his record, too. Biden has always been well within the mainstream of his party, which means that he has moved left as it has. He used to be a strong proponent of the death penalty. During this campaign, he came out for abolition. For most of his career, he opposed taxpayer funding of abortion. But that position has become less acceptable among Democrats, so Biden flipped on that too. . . .