A tied presidential election this year seems more likely than at any point in modern politics, even though the chances are still slim. Should such an event transpire, America could be faced with a situation not seen since the early 19th century — a president and vice president of different parties.

Should the Electoral College tie in November and the body is unable to certify either Vice President Harris or President Trump as the winner, then the election for president and vice president would be handled by the House and Senate, respectively. It could, in a longshot scenario, give America an administration led by Trump and Governor Walz. 

Polling in 2016 and 2020 — which showed both Secretary Clinton and President Biden winning their respective races — wildly underestimated Trump, though surveys have gotten much more accurate since the former president left the White House. According to FiveThirtyEight, pollsters in 2022 were more accurate in gubernatorial, Senate, and House races than at any time in the last 20 years. Should that accuracy carry over into 2024, the razor-thin margins between Trump and Ms. Harris could mean America is headed toward a tie. 

The most likely prospect of a tie is if Ms. Harris falls flat in her two weakest Rust Belt states — Pennsylvania, where the polls have shown a dead-heat for months, and Michigan, where Ms. Harris will undoubtedly face problems with Muslim, Arab-American, and young voters given the Israel–Hamas war. In this scenario, she carries Wisconsin and North Carolina where she has been polling slightly better against Trump, and she captures Nevada and Arizona, where two popular Senate candidates could give her the coattails to overcome Trump. 

She also carries three of Maine’s four Electoral College votes by winning the first district and the state as a whole, as well as the one vote from the second district in Nebraska, which President Biden won in 2020. Should all of those dominoes fall in that direction, both Ms. Harris and Trump would end up with 269 Electoral College votes — each one vote shy of the presidency. 

After months of litigation and public protests demanding recounts and vote audits from both Democrats and Republicans, the vote for president would then be handed to the House, and the vote for vice president to the Senate. 

In the House, each state delegation gets one vote, meaning the party that controls more seats in a delegation would cast their votes for their preferred candidate. It takes 26 votes in the House to win the presidency. 

Assuming minimal changes are made to the composition of the House in the November elections, Trump would be the overwhelming favorite to win. He would take the votes of Wisconsin, North Carolina, Arizona from Ms. Harris’s column despite her winning them in November. Surprisingly, should Congresswoman Mary Peltola hold on this yeaer, Ms. Harris would win Alaska’s vote in January. 

Currently, Republicans control 27 of the 50 state congressional delegations, meaning Trump would have a two-vote margin to win the presidency in the House. 

In the Senate, it would be a different story for the vice presidential race. Each senator is granted one vote for vice president, and whoever emerges with 51 votes is elected. If Democrats are able to run the table in November by keeping every vulnerable incumbent in their seat, while also making sure the Congressman Ruben Gallego and Congresswoman Elissa Slotkin win their Senate races in Arizona and Michigan, then Democrats will have exactly 50 votes. 

Assuming every Democrat votes for Mr. Walz to be vice president and every Republican votes for Senator Vance, the vote would result would be 50 for each man — meaning the tie-breaking vote would come from none other than Ms. Harris, who would still be the president of the Senate by the time the upper chamber voted for vice president in January. She undoubtedly would cast her vote for Mr. Walz, assuring that her running mate ascends to the White House without her under a second Trump presidency. 

The Trump–Walz administration would be in place for four years, given that the vice president is the only person the president is unable to fire from the executive branch. With Democrats’ 50 seats in the Senate and Mr. Walz serving as president of the upper chamber, Senator Schumer would stay on as majority leader.

The vice president’s position would allow Democrats to stall or outright block any legislation Republicans hope to get through Congress, as well as any executive branch or judicial appointees, including Supreme Court nominees.