In the eve on the 2020 U.S. election, tensions are running high.

The good news? 2020 isn’t 2016. Social networks are way better prepared to handle a wide array of complex, dangerous or otherwise ambiguous Election Day scenarios.

The bad news: 2020 is its own beast, one that’s unleashed a nightmare health scenario on a divided nation that’s even more susceptible now to misinformation, hyper-partisanship and dangerous ideas moving from the fringe to the center than it was four years ago.

The U.S. was caught off guard by foreign interference in the 2016 election, but shocking a nation that’s spent the last eight months expecting a convergence of worst-case scenarios won’t be so easy.

Social platforms have braced for the 2020 election in a way they didn’t in 2016. Here’s what they’re worried about and the critical lessons from the last four years that they’ll bring to bear.

Contested election results

President Trump has repeatedly signaled that he won’t accept the results of the election in the case that he loses — a shocking threat that could imperil American democracy, but one social platforms have been tracking closely. Trump’s erratic, often rule-bending behavior on social networks in recent months has served as a kind of stress test, allowing those platforms to game out different scenarios for the election.

Facebook and Twitter in particular have laid out detailed plans about what happens if the results of the election aren’t immediately clear or if a candidate refuses to accept official results once they’re tallied.

On election night, Facebook will pin a message to the top of both Facebook and Instagram telling users that vote counting is still underway. When authoritative results are in, Facebook will change those messages to reflect the official results. Importantly, U.S. election results might not be clear on election night or for some days afterward, a potential outcome for which Facebook and other social networks are bracing.