The Great Political Sort Continues

New York's  House delegation is now 27-2 Democratic, or 93%.  (If you add in the senators it goes up to 94%.)  For comparison, Texas's House delegation is 63% Republican, Florida's is 60% Republican, and California's (counting Garamendi) is 64% Democratic.
In recent memory, has such a large state been so totally dominated by a single party? The largest I can think of are Massachusetts today (100% Dem) and Oklahoma in the late '90s (100% GOP).

While we're at it: Why has the GOP collapsed in rural upstate New York but not in rural central Pennsylvania?  I know there are cultural differences between the two (Yankee vs. Scots-Irish) but it's a striking divide nonetheless.