I agree with Paul Seaton in this thread. The move from “liberal” to “progressive” was mostly a branding response to changing public understanding of the term “liberal.” I can’t find it right now, but in David Frum’s book on the 1970s he wrote about how the meaning of “liberal” changed for lots of formerly Democratic, white working-class voters in the 1960s and 1970s. To exaggerate a little, these voters thought of liberalism as having become pro-mugger, pro-crushing taxation, pro-welfare dependency, and pro-blaming America first. I’m old enough to remember George H. W. Bush mocking Mike Dukakis for refusing to self-identify as a liberal. He said Dukakis wouldn’t go on Wheel of Fortune because he was afraid that Vanna White would turn over the L-word.
The progressive label didn’t have that same stink to the swing-voters of the last dozen or so years. They hadn’t read the Claremont Review or A New Birth of Freedom. For the older voters, Woodrow Wilson was either a name they vaguely remembered from high school history, or maybe Dennis the Menace’s grumpy old neighbor. The younger voters probably lacked even that context. And progressive sounds pretty good. Progress is good right? For left-Democrats who were looking for a change of label and who wanted to differentiate themselves from the more moderate New Democrats, progressive was as good a label as any for the audience they were aiming at.
So how much did this change of label matter? My guess is somewhere between very little and not at all. Changing demographics (I partly agree with commenter Sam Haysom here), the changing media environment and the deep unpopularity of the last administration during a generation’s formative years, were each more important to the increasing political success of the center-left than the change of label from liberal to progressive. How many New Democrats/Blue dog Democrats/Red State Democratic Senators who won elections the last four cycles would have lost if Obama, Pelosi and MSNBC had gone by liberal instead of progressive? Maybe a few older white swing-voters who stayed home would have shown up to vote for Romney if Obama strongly identified as a liberal rather than a progressive, but then again maybe not. I see no reason to think the effect would have been large.
And let’s remember that even the label “socialism” is losing some of its stink. I can’t exaggerate how broken the right-of-center message machine is when it comes to talking to the majority of the country