Tuesday marks six weeks until Election Day and is National Voter Registration Day, a moment to turbocharge sign-ups before it's too late. But the significant blow the coronavirus has dealt to civic engagement this year leaves in doubt how many millions of eligible but still unregistered Americans can be found and converted on the unofficial holiday.

Fresh national numbers from the Brennan Center for Justice, a progressive think tank which does some of the most extensive research on democracy's challenges, confirm the drop in registration compared to the last presidential election. The organization's analysis of 21 states found 17 have watched registration rates plummet since four year ago.

With the first deadlines coming the first week of October in 15 states, a bevy of groups with sometimes similar sounding names have refocused — or been formed — to push the uphill goal of finding millions more willing first-time voters, with an emphasis on younger people.