Demographic changes have made it much more difficult for Republicans to win national elections. In California, the GOP hasn’t won a Senate seat since 1988, and has no discernable prospects for winning there anytime soon. Similarly, at the presidential level, California is impenetrably blue.

Of course, what explains the leftward political tilt in formerly Republican states such as California is immigration, both domestic and Hispanic. Political analyst extraordinaire Larry Sabato confirms this change in today’s Wall Street Journal.

Seven “super swing states with 85 electoral [votes] will determine which party gets to the magic number of 270 electoral votes,” Sabato writes.

The seven states are notable because most of them (five by my count) have been transformed politically by domestic in-migration from other states, as well as Hispanic immigration from Mexico, Central America and the Caribbean.

For example, Colorado (9), Florida (29), Nevada (6), and Virginia (13) have all become key battleground states thanks to Hispanic immigrants. These same four states (plus New Hampshire (4)) also have swung politically as new (and often more liberal) residents move there.

Indeed, New Hampshire has become more hospitable to the Dems because of an influx of residents from neighboring Taxachusetts. The northern Virginia suburbs, likewise, have trended leftward politically, thanks to a growing workforce dominated by younger people who move to Washington to work for and with the government.

The other two key battleground states, Ohio (18) and Iowa (6), do not seem to have been appreciably altered politically by immigration.

There is, however, one glimmer of hope for Republicans. According to Sabato,

The GOP has gotten a quiet advantage through the redistricting following the 2010 Census. The Republican nominee could gain about a half-dozen net electors from the transfer of House seats –and thus electoral votes — from the northern Frostbelt to the southern and western Sunbelt.

Put another way, the Democrats can no longer win just by adding Ohio to John Kerry’s 2004 total. The bleeding of electoral votes from Democratic states would leave him six short of 270.

Ohio, in fact, has lost two electoral votes. Texas, meanwhile, has gained four electoral votes; Georgia and South Carolina have picked up one a piece.

Edited for accuracy and grammar.