As election reforms have become a key issue across the nation, in 17 states independent voters still cannot cast a ballot in primary elections.

This restriction applies to presidential primaries in some of these states, state and congressional elections in others, and all types of primaries in most of these states. (The interactive version of the map below can be viewed here.)

The Democratic and Republican parties in these states jealously guard their taxpayer-funded primary elections by treating independents as outsiders. In reality, independents outnumber both Democrats and Republicans nationwide, with polls showing up to 43 percent of Americans self-identifying as independents.

As a result, the “closed” presidential primaries in 2016 cost taxpayers roughly a quarter-billion dollars, yet they cast aside 26.3 million voters. The party leaders may look at independents with a jaundiced eye, but one poll found 70 percent of the nation’s voters favor open primaries.

As bad as it is that independents in one-third of the states are shut out of the primary process, things used to be worse. In a guest column written for The Hill, John Opdycke, president of Open Primaries, a nonpartisan reform group, reports that some progress has been made.

In 2016, the Democratic Party opened their presidential primaries to independents in Oklahoma, South Dakota, Nebraska, California and Alaska. So did the Republican Party in Alaska.

In several states, according to Opdycke, activists are pushing to open their primaries before the 2020 elections. But the timeline is surprisingly short as party leaders in all states will set the rules for the next election by the summer of 2019.

In most states, voters register as a Republican or Democrat – or, in some cases, as an independent. But the two parties are in control as they establish the procedures for the primary election process in each state. In fact, the U.S. Supreme Court has ruled that the state parties can open up primary elections to independents even if state law forbids such a move.

In Michigan, where voters do not declare their political affiliation when registering, the primary system is considered open though voters must choose either a Democratic or Republican ballot at the polls.

Groups such as Open Primaries and the Independent Voter Network are leading the way in a grassroots push to end closed primaries. In some cases, lawsuits have been filed. But Opdycke warns that GOP leaders in a few states are hoping to make participation in primaries more restrictive, not more inclusive. And some Democratic leaders go so far as to argue that independents don’t really exist, so voters who lean toward the Democrats should declare themselves a party member.

Opdycke offers this view as the 2020 elections loom on the horizon:

Leaders in both parties may wake up and realize it is in their self-interest to roll out the red carpet to independent voters, whose votes they will desperately need in November in closed primary battleground states like Florida, Pennsylvania and Arizona. The DNC (Democratic National Committee) and the RNC (Republican National Committee) penalize state parties if they attempt to move the date of their presidential primary too far forward. They could adopt a similar posture towards the inclusion of independents, penalizing state parties that don’t allow them to cast a ballot. After all, it’s harder to say “vote for us” in November after asserting “no independents allowed” in March.