Using Jimtex's perimeters of urban clusters, and using a cutoff of say 1,000,000, the only one's I can think of are Cincinnati, Phoenix, San Diego, Sacramento and Milwaukee. Have I missed any?
How about Jacksonville, FL?
Indeed it is. And I missed Pittsburg (Pub enough by a considerable margin), Baltimore (Pub enough by a bit), and Buffalo (big enough). Missing the cut are Albany (not big enough), and Richmond (big enough barely but not Pub enough by a bit). I suppose one could check Dallas, but I doubt it makes the cut. And Indianapolis (which I had checked before), is not Pub enough.
I expect the Pittsburgh metropolitan area to start trending Democrat, though. Allegheny County has been trending Democrat since 2000, and the city of Pittsburgh in particular has been trending liberal Democrat. The Allegheny County Chief Executive was a moderate Republican from 1999-2003, a moderate Democrat from 2003-2011, and has been a liberal Democrat since 2011. It's also worth noting that Barack Obama still won Allegheny County minus the city of Pittsburgh in 2012, so the perception of a moderate city surrounded by conservative suburbs is obsolete. Pittsburgh is now an increasingly liberal city surrounded by moderate suburbs in Allegheny County. This data gets washed out at the metropolitan level since Allegheny County contains just over half of the metropolitan population.
Though the six outer counties in the metropolitan area have been trending Republican, four of those six counties are losing population, and the two that are gaining population aren't gaining as fast as they used to. At the same time, Allegheny County has begun gaining population again. Furthermore, the large elderly population in the metropolitan area has begun dying off in the last 10 years, and it's this elderly population that has given Pittsburgh a socially conservative reputation in the first place. The city of Pittsburgh has gotten younger since 2000, and is now younger than the national average for the first time in decades. The median age in Allegheny County is flat, and the proportion of elderly is now smaller than it used to be.
Basically, we're seeing two trends at work: a Democrat trend in a revitalized Allegheny County, and a Republican trend in the stagnant outer metropolitan counties.
