In the last four presidential elections in a row, the Republican candidate has won states geographically stretching from Georgia to North Dakota, Montana and Idaho — from the Atlantic Ocean, across the Mississippi River to the Great Plains and north to Canada.
The coalition helped President George W. Bush win two elections, but John McCain and Mitt Romney still kept the "Republican L" intact even in their losses. Given the Republican strongholds in southern states and plains states, from Texas straight north to North Dakota, it was fairly easy to assume going into 2016 the Republicans could draw an L-shaped line over states they would win from the Atlantic Ocean to Canada.
That is, until the party nominated Donald Trump. Now the "Republican L" is in question.
Trump seems fairly likely to win the vertical part of the L, from Texas through North Dakota, although Kansas could be a problem. And in the Atlantic Coast region, he comes into a lot more trouble.
To complete the L, Trump would have to win Florida, Georgia, North Carolina or Virginia. South Carolina alone would not be sufficient, as it's cut off from points west by North Carolina and Georgia.
Since Trump is running behind past GOP candidates in national polls, assume Hillary Clinton wins Florida and Virginia, which President Obama won in 2012.
North Carolina also seems like a stretch for Trump. Although Clinton only has a 2 percentage-point lead there, on average, most political forecasters say the race there leans toward Clinton.
That leaves Georgia as Trump's last chance to complete the Republican L (he should be thankful the state's map was drawn with a 100 mile-long coastline). The last time Georgia voted for a Democratic presidential candidate, it went for Bill Clinton in 1992.
But in the RealClearPolitics average of polls, Clinton currently leads there by 0.3 percentage points. Bettors only give Trump a 58 percent chance of winning Georgia. By Election Day, the state will probably lean toward Trump, but it's not a foregone conclusion for the first time since 1996.
Part of the reason Trump is having trouble with the L could be the rise of third-party candidates in this election. If it weren't for 1992 and 1996, the streak of the Republican L would stretch back through the 1980 election.
But the 1992 and 1996 elections are unusual in that the Republican and Democratic candidates combined for less than 90 percent of the vote. For comparison, Romney and Obama got 98.3 percent combined in 2012. It could just be coincidence, but the correlation is there. It also helped that Clinton had Arkansas locked down for the Democrats.
Trump's candidacy has already defied conventional expectations in plenty of ways. Breaking the Republican L might be added to the list.
Jason Russell is a commentary writer for the Washington Examiner.