America needs at least two healthy political parties, and right now, with Republicans attacking the legitimacy of the Democrats, we are in danger of having none.

For the past generation, Republicans have tried to delegitimize the Democrats. Calling their opponents “socialists,” Republicans have suppressed Democratic voters and gerrymandered congressional districts to shut Democrats out of the government. When voters elected Democrat Barack Obama president, Republican lawmakers vowed not to work with him, and scrapped the norms of our system to slash his power. Now, with Trump trying to steal a presidential election and Republican lawmakers looking the other way, we are on the verge of becoming a one-party state.

The Republican assault on the legitimacy of the Democrats is a profound assault on American democracy, which since 1800 has depended on a party system for stability. Political parties provide an organized way to oppose the existing government’s policies or leaders and to keep them more or less honest, as every move of ruling lawmakers comes under scrutiny.

The Founders hated the idea of parties, and hoped that all Americans would unite under a single virtuous leader, who ruled for the good of all and whose citizens recognized his policies as beneficial and disinterested.

They put George Washington in charge, as virtuous a leader as they could imagine. And yet, almost immediately, Americans began to divide into two political camps. The Democratic-Republicans organized under Thomas Jefferson to oppose the policies of Washington’s Federalists. As the Federalists flexed the muscles of the new government, Jefferson and his friends attacked them as monarchists.

It turned out that, even with a leader as dedicated to the good of the nation as Washington was, government policies inevitably sparked disagreement.

What the Founders discovered is that competing political parties are vital to a democracy. Opposition leaders act as watchdogs to keep leaders accountable to the people. An opposition party also stabilizes the government. It enables people who don’t agree with the leaders currently in charge to envision putting their own ideas into practice. They can continue to support the government even if they disagree with its current lawmakers, knowing that, if they can garner enough support, they can win control of the government and enact policies they prefer. This is precisely what Jefferson did in 1800.

That election was crucial to the success of our democratic government because it proved that our government could change hands peacefully. Now, that hallmark of American democracy, the peaceful transfer of power from one party to another, is under assault. Republicans under Donald Trump are indicating they will not consider a Democratic win legitimate, and will fight to keep Trump in office no matter what the voters say.

If we manage to fend off this specific attack on our democracy, the larger Republican assault on the legitimacy of the Democrats must also be defeated.

The attempt to turn us into a one-party state undermines the system that has stabilized our democracy for more than two centuries. If opponents of a regime have no hope of regaining control of the government through an election and the peaceful transfer of power, they will work to undermine the system piecemeal, through individual acts of resistance. Those in power retaliate with arrests and violence. Trying to shore up their power, they declare that anyone voicing any opposition to the government is a traitor, and act accordingly.

These days, it appears that some of the president’s supporters are comfortable with such an outcome. But the thrill of “owning the libs” will be brief.

Without a watchdog over ruling lawmakers, they invariably become more and more corrupt, and without an opposition that has a chance of regaining power, there will be no way to stop them. Right now, Republican leaders still need votes. But eliminate the Democrats, and they will no longer need loyal voters.

They will be able to act however they wish.

Mаtt Mаhurіn

Letters from an Аmerican is a daily email newsletter written by Heather Cox Richardson, about the history behind today’s politics