I'm a bit late on this question, but this is a great explainer from Daily Kos Elections on why yes, Democrats should be targeting (among other places) affluent suburbs as part of the strategy to turn America blue. It is responding to an NYT editorial which suggested such targeting would cause the Democratic Party to abandon important progressive values, since affluent suburban (coded as White) voters are thought to be prime constituencies demanding policies harmful to poorer or brown citizens.
The DKE piece does a good job problematizing several assumptions in the NYT article (including the belief that these suburban districts are all uniformly or predominantly White), but I particularly like the way it pays attention to voter psychology.
One might think that people come to beliefs on clusters of issues, and then vote for the Party that best matches their preferences. And sometimes that's true -- but usually only for a small band of exceptionally salient issues which the voter cares a lot about. On other issues -- the vast majority --the causality runs in the opposite direction, with people tending to follow their team. Hence, if people identify as "team Democrat" they'll likely shift their views towards consensus Democratic Party positions. This is one of the reasons why White Democrats have in fact shifted hard to the left on issues of racial justice in America over the past few years -- that position is now part of what it means to be on "team Democrat", and so self-identified Democrats adjust their views accordingly.
We see this all the time -- a recent prominent case is the surge in favorable Republican sentiment towards Vladimir Putin, almost certainly driven not by any considered judgment about the merits of Putin but rather by the sense that Russia and Putin are "on their team" and anti-Russia and anti-Putin sentiment are associated with Democrats. The almost complete absorption of southern Evangelical political ideology into that of the Republican Party is another case. On the other side, Muslims have become considerably more liberal on social issues since 9/11 -- not coincidentally, they've also moved from a Republican to a Democratic constituency at the same time stemming from the GOP's open embrace of Islamophobia. One suspects that a similar dynamic accounts for American Jewry's general across-the-board liberalism -- I'd love to attribute it to some intrinsic progressive characteristic of my people, but it's probably more a function of what segments of American society welcomed us onto their team and what segments pushed us away.
This account of how social groups develop political ideology is not the most popular secret in Political Science. It suggests that the route to political change isn't deep reflection on matters of truth and justice but simply relatively passive games of "follow the leader" and partisan feedback loops. But results are results. And in the case of progressive commitments on issues of racial justice, the more White suburban voters view themselves as consistent Democratic voters, the more likely they'll be to back progressive political commitments across the board.