OK, Gallup has a road map poll for the general election (conducted through May, which is to say prior to Obama sewing up the nomination) that gives us a good baseline going forward. Yes, Virginia, there’s still a big religion gap–19 percentage points among those who say they attend worship services at least weekly. That’s par for the course in presidential voting since 1992. The reverse gap among those who seldom or never attend is 16 points, while those in between divide perfectly evenly.
On the choice by tradition, Protestants (i.e. non Catholic Christians) are all lumped together, and they are McCain’s best group, splitting for him 51 percent to 41 percent. Given that this includes African Americans, it signals the usual big white evangelical numbers for the GOP candidate. Catholics divide evenly, 46-45 for McCain–which suggests that white Catholics are moderately strongly pro-McCain and Latino Catholics very strongly pro-Obama: no surprise. Jews split 57-35 for Obama–down double digits for the Democratic candidate in the Clinton-Gore-Kerry elections, in Reagan territory. Finally, there are those of no religion, the Nones; they prefer Obama by a whopping 40 points, 66 percent to 26 percent. That’s 15 percent of the electorate, folks, and Obama’s ace in the hole.