President Trump has just claimed in a speech that he is being cheated out of victory in the 2020 election. He has stated that his votes are “miraculously getting whittled away in secret.” Trump presented no evidence to support his claims, which have been widely ridiculed by independent observers.

Trump’s speech comes at a moment when it appears increasingly likely that he will not get enough votes to be reelected (counting continues in states including Arizona, Nevada, Pennsylvania, Georgia and North Carolina). It is unprecedented in modern U.S. history for a president to make such remarks. And they will have consequences. Political science gives strong reason to believe that such claims, unsupported by evidence, may corrode American democracy. Here is why.

Democracy is a system in which losers recognize that they have lost

Political scientists think of democracy as a system that is based on shared rules and expectations that allow people who disagree with each other to live in (relative) peace. Citizens may disagree, sometimes very strongly, over basic issues. They can settle these disagreements through putting them to the vote, or, more commonly, by voting in regular elections for politicians who then decide and implement on their behalf.

But it is important that no government lasts forever in a democracy. As the prominent scholar Adam Przeworski describes it, democracy is "a system in which parties lose elections.” A democracy in which the party that has lost an election fails to leave power is no longer a democracy.

This is not the situation that the United States is in. Although President Trump refuses to recognize that he is likely to lose the election, he has suggested that he will go to the courts to seek relief for the cheating that he claims has occurred. But his baseless claims will still damage democracy.

Democracy depends on beliefs in fair process

It isn’t fun for anyone to lose an election, whether they be voters or politicians. What makes their unhappiness bearable is the belief that they will have a chance to try again. Those who have lost the election know that there will be a new one, where they have another chance at persuading enough voters to give them a win.

But this, of course, works only if people believe that the election is at least somewhat fair. They will have no incentive to accept election results or to participate if they expect that the elections are rigged by their opponents so that they will never have a chance to win.

So what happens when a political leader tells his followers that he is losing only because the other side is cheating? These followers – if they believe him – are likely to stop believing in democracy. They will think that the game is fixed so that they have no opportunity of winning.

In a worst-case scenario, this can lead to accelerating democratic breakdown. If the people on one side believe that democracy is systematically rigged against them, they are unlikely to submit to the democratic process and may instead turn to other means to protect their interests. This may, in turn, provoke a spiral of retaliation and counter-retaliation.

“Regulating conflicts by elections is then self-enforcing. Violence and other costly forms of conflict are avoided by the mere fact that the political forces expect to take turns. Yet this mechanism fails when the short-term stakes in an election are too high or when the opposition sees no chance to win according to rules.”

Even if this kind of breakdown doesn’t happen, faltering beliefs in the fairness of the system may make political institutions increasingly unworkable as people take advantage of whatever possibilities exist to cement their own control, believing that this is the only way to protect themselves against the other side, which will do the same or worse.

Some other key Republicans are supporting him

Initially, many key voices in the Republican Party were notably unwilling to endorse Trump’s allegations of cheating. Former Republican senator Rick Santorum has expressed the hope that Republicans “will stand up at this moment and say to Trump what needs to be said.” However, prominent Republicans including Sen. Lindsay Graham (R-S.C.) have now come out to support Trump’s allegations. Graham went so far as to suggest that “everything should be on the table,” including having the Republican state legislature invalidate the vote on the basis that Philadelphia elections are as “crooked as a snake.” Such statements may do long term damage to American democracy, both by making Republican voters believe that the election was rigged, and by suggesting to Democratic voters that Republicans are willing to overturn democratic elections when they do not like the outcomes.