Spurred by the Supreme Court, a Nation Divides Along a Red-Blue Axis

Pressed by Supreme Court decisions diminishing rights that liberals hold dear and expanding those cherished by conservatives, the United States appears to be drifting apart into separate nations, with diametrically opposed social, environmental and health policies.

Call these the Disunited States.

The most immediate breaking point is on abortion, as about half the country will soon limit or ban the procedure while the other half expands or reinforces access to reproductive rights. But the ideological fault lines extend far beyond that one topic, to climate change, gun control and L.G.B.T.Q. and voting rights.

On each of those issues, the country’s Northeast and West Coast are moving in the opposite direction from its midsection and Southeast — with a few exceptions, like the islands of liberalism in Illinois and Colorado, and New Hampshire’s streak of conservatism.

Even where public opinion is more mixed, like in Ohio, Wisconsin, Georgia, North Carolina and Texas, the Republican grip on state legislatures has ensured that policies in those states conform with those of the reddest states in the union, rather than strike a middle ground.

The tearing at the seams has been accelerated by the six-vote conservative majority in the Supreme Court, which has embraced a muscular states-rights federalism. In the past 10 days the court has erased the constitutional right to an abortion, narrowed the federal government’s ability to regulate climate-warming pollution and blocked liberal states and cities from barring most of their citizens from carrying concealed guns outside of their homes.

“They’ve produced this Balkanized house divided, and we’re only beginning to see how bad that will be,” said David Blight, a Yale historian who specializes in the era of American history that led to the Civil War.