House Speaker Nancy Pelosi, D-Calif., urged her congressional colleagues to bolster their support for Democratic candidates in an attempt to shore up the type of majority the party would need if the 2020 presidential election reached her chamber.

According to the 12th Amendment, congressional delegations decide the next president in the unlikely event that neither candidate wins a majority (270) in the Electoral College. Going into the election, Trump has the upper hand as his party controls more state delegations (26 vs. Democrats’ 22), even though Democrats outnumber Republicans in total representatives.

But because Congress doesn’t declare election results until after new members are sworn in, November’s results could theoretically allow Democrats to win enough state delegations prior to Congress certifiying the election results on Jan. 6.

“We must achieve that majority of delegations or keep the Republicans from doing so,” Pelosi said in a letter to colleagues Sunday. “Because we cannot leave anything to chance, House Majority PAC is doing everything it can to win more delegations for Democrats. It’s sad we have to have to plan this way, but it’s what we must do to ensure the election is not stolen.”

She added: “That’s why it’s so important that we support House Majority PAC right now.  We have outstanding candidates in these key districts and they have built strong campaigns, but we must forcefully ensure they win. Simply put, this strategy to protect our democracy and elect Joe Biden will take an all out effort and resources.”

Pelosi’s comments underscored the tension surrounding an election where polling showed narrowing margins between the two candidates just weeks before voters are set to cast their ballots.

While the election could be a close call, the scenario outlined by Pelosi hasn’t occurred since 1876. But in the unlikely event that it does, Pelosi wants her caucus to be prepared.