Thomas Donlan‘s latest editorial commentary in Barron’s explores the Republican Party’s attempt to cope with divisions exposed by Donald Trump’s presidential nomination.

It’s not official yet, but it seems certain: The Republican Party is a house divided against itself. In its early days, Abraham Lincoln recalled the words of Mark’s Gospel and warned that the nation divided could not stand. These days, the warning is true of Lincoln’s party.

The Republican Party could go the way of the Labour party in the United Kingdom in 1979: After choosing radicals to lead them, party members cheerfully turned their backs on their moderate colleagues.

Working with the traditional third party, the Liberals, the Labour moderates turned the U.K. over to Margaret Thatcher. Although Thatcher was very good for the country’s economy, her opponents would not recognize her successes. They denounced her over and over again and suffered three defeats. Thatcher never won a majority of the nation’s votes but held majorities of the seats in Parliament from 1979 to 1990. …

… Both U.S. political parties have long records of success when they fudge their differences and try to please as many voters as possible. When both parties work like that, we have close elections and often get divided government. The parties enjoy special success when the opposition is attempting to purge a faction. The saving grace after such landslides is that the losing party comes to value discipline more than purity.

The election of 2016 may not have any such saving grace after the campaign turned to Trump’s using offensive language to brag about sexual conquests that may have been sexual assaults. Although he had said much the same things in books and interviews, a revealing and repulsive video leaked on Sept. 30 was the last straw for many grudging Trump endorsers, such as House Speaker Paul Ryan.

“It’s every person for himself or herself right now,” said former Republican Sen. Judd Gregg of New Hampshire. “The nominee for president is so destructive to everyday Republicans.”

Trump declared last week in a tweet that defecting Republican officeholders and contributors had liberated him to “fight for America the way I want to.” Inspired by that, some of his supporters defected from the defectors, refusing to support Republican candidates for Congress who don’t back Trump. …

… Trump sounded almost gleeful in another tweet: “So many self-righteous hypocrites. Watch their poll numbers—and elections—go down!”

It’s difficult to imagine Trump getting such a wish and also winning the White House if local races are dragging the ticket down. It’s even harder to imagine him governing with congressional members of both parties more hostile to him than Republicans have been to Barack Obama. But it’s easy to imagine Trump as an embittered loser loudly dividing the party for years to come.