I have seen a lot a skepticism lately about relying on courts to protect the equal right of eligible voters to participate in an election by casting a ballot and having it counted accurately. But unless Congress is going to exercise its constitutional power to create an entirely new federal bureau of election administration to run congressional elections (and states would willingly let this new federal bureau administer other elections, like gubernatorial and the popular vote to appoint presidential electors), what’s the alternative?

How can we tell if every eligible voter who wants to cast a ballot is meaningfully able to do so in a specific election (like the upcoming midterms)–and thus is not being denied their fundamental right to vote? First, assuming a state does not have same-day registration, the voter must have an adequate opportunity to register in advance. While same-day registration certainly makes access to the ballot easier, I would not argue that the absence of same-day registration is a denial of the right to vote, as long as the state provides its eligible citizens with a genuine opportunity to register in advance. If state officials failed to do that, in violation of existing federal law, it would be necessary to turn to the courts to enforce that right. (And even if federal law were to require same-day registration nationwide, it would be necessary to rely on federal-court enforcement of that right in the event of noncompliance, deliberate or otherwise, by state and local election officials.)

Assuming eligible citizens have a meaningful opportunity to register in advance, what about their opportunity to cast a ballot? The essential role of provisional ballots, as required by HAVA, should not be overlooked in this respect. All voters who believe themselves to be registered have an existing federal-law right to cast a provisional ballot. I worry about long lines at the polls as a practical obstacle to voters wishing to cast a ballot, including a provisional one if necessary, but voters who want to make sure they are not denied their right to vote must insist that they cast at least a provisional ballot and refuse to leave their polling place without being able to do so. If state and local officials fail to comply with this existing federal-law obligation to give a provisional ballot to all voters who request one, it would be necessary to go to court seeking an emergency TRO to make sure these provisional ballots get into voters hands while they remain waiting in line.

Compliance with the existing federal-law obligation to give voters provisional ballots is especially important in a presidential election for this reason: if voters who want to cast a ballot but who are denied the opportunity to cast one and leave their polling places without casting one, there is no possibility of a do-over after Election Day has passed, at least not under existing federal law. Why? Because if the claim is that a state’s popular vote in a presidential election is fundamentally defective because there were a group of voters (say, for example, many in Atlanta) who were denied their right to cast a provisional ballot, then the popular-vote election for the purpose of appointing the state’s electors will have “failed to make a choice on the day prescribed by law” under 3 U.S.C. 2, thereby giving the state’s legislature the right to choose an alternative method of appointing electors (including direct appointment by the legislature itself).

Thus, as we contemplate the possibility of partisan state and local election officials (along with partisan state legislatures) attempting to engineer electoral outcomes in contravention to free and fair elections, including by denying eligible citizens the right to cast a ballot, we ultimately must rely on courts to uphold the law that guarantees the right to cast a ballot. Above all, this includes the key provisions of the federal Help America Vote Act that insist that no voter be turned away from the polls without having a chance to cast a provisional ballot, which must eventually be counted if indeed the voter was registered and eligible to participate in the election as the voter believed. I’m afraid that, as we think about how to safeguard democracy from the very real dangers that exist, we are neglecting the need to remain vigilant about the judicial protection, if necessary, of the essential right to cast a provisional ballot.