Jonah Goldberg has a list of books on modern liberalism/progressivism at National Review.
I haven’t read any of them, so I have to take his word that they’re
worthwhile. One paragraph stands out and echoes something I heard over
the weekend about the left’s preference for grassroots activism and
organizing.

As I’ve written a bunch of times, I think liberals have cut
themselves off from their own intellectual tradition, to the point
where the giants of the true liberal tradition ? Locke, Smith, the
Founders, etc. ? are vastly more celebrated on the right than on the
left. But even the founders of “modern liberalism” (i.e.
Progressivism), which means almost the exact opposite of traditional
liberalism, are very rarely celebrated by self-described liberals
today. Don’t take my word for it ? E. J. Dionne admits as much in his
book Stand Up Fight Back:
Liberals and Democrats tend not to view themselves as the inheritors
of a grand tradition.
Almost on principle, they are suspicious of such
traditions, of too much theorizing, of linking themselves too much to
the past.” Modern liberalism has lots of intellectual giants, but liberal totem poles tend to feature activists more than thinkers and
writers
. Indeed, of the intellectual giants who formed (or deformed)
modern liberalism ? Herbert Croly, John Dewey, Reinhold Niebuhr, et al.
? “not one of them is routinely celebrated by today’s liberals,”
according to Dionne. (Meanwhile, the avatar of movement liberalism
these days ? that Daily Kos guy ? admits he doesn’t really read books much at all).