For anyone concerned about democratic norms and the rule of law, the 2016 election offered a clear lesson: Parties need to exercise more control over candidate selection. In this era of high partisanship, the official party nomination puts any candidate within striking distance of the presidency. This great power thus carries a profound responsibility: to deny the party endorsement to would-be demagogues. So why are Democrats reducing the role of party elites in the primary process this time around?

The changes Democrats have made to the nomination process were prompted by Hillary Clinton’s win over Bernie Sanders in the 2016 Democratic primary. That victory generated accusations that her campaign was coordinating with the Democratic National Committee to rig the nomination contest. Wary of such charges, the party has since scaled back its influence over the primary process. First, so-called superdelegates — party leaders and elected officials — were stripped of their power to decide a closely contested nomination on the first ballot at the party convention. These elites had previously played an important role in the nominating process; though they typically supported the candidate who won the nomination via primary and caucus victories, their presence helped make support from party elites an important factor in the primary campaign.

Democrats should know better than to diminish their control over their own nomination process.

Democrats also yielded to pressure to open access to presidential debates. In fact, they’ve now promised to include any candidate with 65,000 donors on the debate stage, in addition to those with qualifying levels of polling support. Not surprisingly, this rule is already being gamed: Recently, the Washington Post reported that John Delaney, a wealthy former member of Congress, is matching $1 donations with $2 contributions to charity to try to attract enough support to be included despite having no measurable support in polls.

This debate inclusion rule is shortsighted. Should the self-help guru Marianne Williamson be included on stage with Bernie Sanders, Kamala Harris, and Elizabeth Warren if she attracts enough donations? Her staff claims she’s likely to qualify. And as Politico’s Bill Scher points out, loathsome figures, like David Duke, might be able to raise enough donations to participate as well. What would Democrats do then? In a world of ubiquitous small-dollar fundraising, 65,000 donors might not be an insurmountable threshold for fringe candidates.

Americans frequently malign political parties, but they play a critical role in our democracy. While voters (and, by extension, the Electoral College) determine who is elected to public office, it’s the responsibility of parties to put forth their best candidates for those offices. There is no rule or principle stating that party nominees must be selected by popular vote. Indeed, party insiders chose presidential candidates in the U.S. until recent decades (and continue to do so in many other democracies).

More recently, however, the parties have moved toward increasingly plebiscitary systems in which the delegates required to win the nomination are allocated based on voting in statewide primaries and caucuses. The most notable failure of this system came, of course, in 2016. During his campaign, Donald Trump engaged in a clear pattern of authoritarian behavior, including encouraging political violence at his rallies. Such behavior should be disqualifying for any candidate, especially one who aspires to our most powerful office. However, the GOP failed to screen him out, defying expectations that party insiders exerted an important level of control over the process. Though Trump attracted virtually no support from Republican elites, he took advantage of saturated media coverage and favorable delegate allocation rules to help him convert his early polling lead into an insurmountable advantage.

In a general election, the pressures of partisanship and competitive elections ensure that few legislators will cross party lines. Once Trump won the nomination in 2016, GOP elites felt compelled to fall in line, which helped him maintain very high rates of support among Republican identifiers. With his party base firmly in place, Trump built a strong enough electoral coalition to capture the presidency, where he continues to challenge democratic norms and practices. Expert ratings show a consistent decline in the quality of democracy in the U.S. since Trump took office.

In their book, How Democracies Die, the political scientists Steven Levitsky and Daniel Ziblatt emphasize the danger of parties, and other elites, failing to screen candidates effectively, early in this process. Our record on this score is enviable. Though the U.S. has never been free of demagogues and has a terrible history of racial oppression, the parties have largely denied figures like Huey Long and George Wallace access to high office. By contrast, other countries have seen such figures enter the mainstream and acquire power. All too often, the result has been an erosion of democratic norms and institutions. “Blatant dictatorship — in the form of fascism, communism, or military rule — has disappeared across much of the world,” Levitsky and Ziblatt write. “Since the end of the Cold War, most democratic breakdowns have been caused not by generals and soldiers but by elected governments themselves.” For instance, Freedom House, a democracy watchdog, now rates Hungary as only partly free because of the deterioration of its democracy since Viktor Orbán took power.

Democrats see what is happening to democracies across the world; they should know better than to diminish their control over their own nomination process. The move to open their presidential primary process contrasts sharply with the party’s approach to the candidates who they most fear — primary challengers to incumbent legislators. Curiously, the Democratic Congressional Campaign Committee, the party’s House campaign arm, announced last week that it will punish campaign vendors and consultants who work against its members in Congress by refusing to contract with them or recommend them to its candidates. By essentially penalizing primary challengers to incumbent legislators, the party seems intent on preserving that status quo.

This decision leaves us with a paradox: Why are Democrats so willing to screen candidates for office at lower levels but abdicating their role in the campaign for the highest office in the land?