Voter suppression efforts may have changed the outcomes of some of the closest races last week. And if the Supreme Court lets these laws stand, they will continue to distort election results going forward.

The days of Jim Crow are officially over, but poll-tax equivalents are newly thriving, through restrictive voter registration and ID requirements, shorter poll hours and various other restrictions and red tape that cost Americans time and money if they wish to cast a ballot. As one study by a Harvard Law School researcher found, the price for obtaining a legally recognized voter identification card can range from $75 to $175, when you include the costs associated with documentation, travel and waiting time. (For context, the actual poll tax that the Supreme Court struck down in 1966 was just $1.50, or about $11 in today’s dollars.)

Whatever the motivation behind such new laws — whether to cynically disenfranchise political enemies or to nobly slay the (largely imagined) scourge of voter fraud — their costs to voters are far from negligible.

It’s still early to definitively quantify the effects that these laws had on national turnout or on the outcomes of individual races. Initial estimates suggesting that turnout rates sank to their lowest level since 1942 look pretty damning, but so many factors can affect turnout (weather, ballot initiatives, the perceived closeness of races, etc.) that it’s hard to isolate the effects of a single change. More data and statistical analysis expected next year will help.

In the meantime, some ­back-of-the-envelope calculations from Wendy Weiser — director of the Democracy Program at New York University’s Brennan Center for Justice — should at least give us pause: Right now, it looks like the margin of victory in some of the most competitive races around the country was as big as the likely “margin of disenfranchisement,” as Weiser puts it. That is, more people were newly denied the right to vote than actually cast deciding ballots.

Take, for example, Kansas.

In the state’s nail-biting gubernatorial race, Republican incumbent Sam Brownback bested his Democratic challenger, Paul Davis, by a mere 33,000 votes out of nearly 850,000 cast. Now, compare that with the estimated effects of Kansas’s new restrictions on voting.

We know that more than 21,000 people tried to register but failed because they lacked the necessary “documentary proof of citizenship” required by a new Kansas law. The state’s separate, strict voter ID law also had an effect: Applying findings from a recent Government Accountability Office report that examined how the voter ID law affected the state’s turnout in 2012, Weiser estimates that it probably reduced turnout this time around by about 17,000 votes.

Weiser finds similarly troubling results for close races in other states with restrictive voting laws, including North Carolina (where the U.S. Senate race was decided by about 47,000 votes, or 1.6 percentage points, in favor of the Republican candidate) and Florida (where the governor’s race was decided by about 66,000 votes, or 1.1 points, also in favor of the Republican).

Of course, we don’t know how the disenfranchised would have voted, and whether their votes would have flipped these races’ results. Restrictive voting laws tend to disproportionately affect certain groups that lean Democratic — minorities, the young, the poor — but such groups do not vote exclusively for Democrats. And another group that is frequently hurt by voter ID laws, the elderly, tends to lean Republican. For all we know, Virginia’s restrictive new voter ID law actually helped Sen. Mark Warner, a Democrat, narrowly “steal” victory from his Republican challenger (by just 16,000 votes!) because lots of elder conservatives lacked adequate idenfication documents.

If — when more data trickle in and statistical models get more finely calibrated — we learn that voter suppression efforts did indeed change election outcomes, no recourse would be available to disenfranchised constituents, or to candidates wrongly denied office. The courts (and other bodies that have the power to overturn elections) very rarely call for a revote, even when elections are fraught with obvious electoral malfeasance or incompetence. As those of us who were in Florida in 2000 well remember.

The best we can hope for is that the Supreme Court recognizes the damage these controversial laws have done — not just to individual voters’ rights, but to Americans’ confidence in the integrity of the democratic process more broadly — and strikes them down. Otherwise, should the current system stand, expect more protracted, Bush v. Gore-type battles in our immediate future.