In the old days, the U.S. Supreme Court took strong steps to protect the right of ordinary citizens to vote. But culminating in the recent Shelby County, Ala. v. Holder decision that struck down the preclearance provisions of the Voting Rights Act, the Supreme Court in the past decade has turned its back on protecting the franchise, especially for the poor and minority groups.

In 1915, the court struck down the notorious grandfather clause established in many Southern states, which allowed persons to vote only if their grandfathers could. That was a crude device to disenfranchise the descendants of black slaves, who, of course, could never vote. In the 1940s and 1950s, the court held that the Democratic Party in the Southern states could not treat its primaries as a private affair, open only to white voters. In 1964, the court established the one-person, one-vote rule, so that states could not apportion districts in a manner that allowed rural voters to have 50 times the voting strength of their urban counterparts.

In 1966, the court first upheld the constitutionality of the Voting Rights Act, which established federal control over states and other political entities that had used one or another blatantly discriminatory devices to prevent African-Americans and other minority voters from casting ballots. In the same year, it struck down a Virginia poll tax law that required state residents to pay $1.50 a year for the right to vote in state elections. (The 24th Amendment, adopted in 1964, prohibited poll taxes for federal elections.)

Each of these discriminatory devices was imposed by existing political power groups to limit the franchise to those who supported them — and to keep minorities and the poor from challenging their authority. The court saw through the excuses offered by those who defended each discriminatory system and insisted that everyone should have the right to vote and to have his vote count equally.

Then, beginning in 2000, something changed. First came Bush v. Gore, which stopped the efforts of Florida canvassing boards to recount about 60,000 undervotes statewide (votes where the counting machines failed to record the actual choice made on the ballot). The court held that the differing standards used by the canvassing board to count or not count a ballot somehow violated the equal protection clause. A later recanvassing of the votes by various news organizations showed that if rejected votes statewide had been counted (as opposed to only the four counties that were the immediate focus of the decision), Al Gore would have won the presidency. Bush v. Gore w as unlike any of the court's 20th century voting decisions. Not only did it announce a rule that benefited a particular party and candidate — and fractured the court on seemingly partisan lines — but it accomplished this result by ordering that lawfully cast ballots not be counted.

In 2004, the court held that a blatantly partisan reapportionment plan passed by a Republican-controlled legislature in Pennsylvania did not violate the Constitution. Two years later, it upheld a Texas plan that redrew district lines in the middle of the decade (leading to the election of five additional Republican members of Congress) even though there had not been any intervening census. In 2008, the court made the strongest retreat from enforcing voting rights. It refused to strike down an Indiana law that required government-issued photo identification before a person could vote. Justice David Souter wrote in dissent that the voter ID law "threaten[ed] to impose nontrivial burdens on the voting rights of tens of thousands of [Indiana's] citizens," estimating that 43,000 eligible voters — including poor and elderly people, disproportionately members of minority groups, who do not own cars and therefore did not have a driver's license — lacked the kind of identification the law required. The primary justification advanced for Indiana's law was to prevent voter fraud. But the type of voter fraud covered by the law — a voter showing up at the polls claiming to be someone he is not — had never occurred in Indiana! As Souter points out: "The state has not come across a single instance of in-person voter impersonation in all of Indiana's history." So ostensibly to prevent a problem that does not exist, the state (and its Republican office holders) passed a law that burdened and had the potential to disenfranchise tens of thousands of voters, primarily poor minorities. And the high court, which had aggressively injected itself into Florida's administration of its election laws in Bush v. Gore pronounced itself unwilling to look beyond Indiana's asserted "policy judgment."

Other states have been quick to follow Indiana's lead. Since 2011, photo ID laws have been adopted in 15 states, most controlled by Republicans. Acting under the Voting Rights Act, the Justice Department challenged the photo ID laws passed by Texas, South Carolina and Mississippi, but those challenges are now mooted by the decision in Shelby County, and those laws can go into immediate effect.

In Shelby County, the court, in a 5-4 decision, decided that times have changed. Chief Justice John Roberts Jr. wrote: "[T]he conditions that originally justified these measures no longer characterize voting in the covered jurisdictions." He noted that many more blacks were registered to vote than in 1965. Under the law, "States must beseech the Federal Government for permission to implement laws that they would otherwise have the right to enact and execute on their own," Roberts wrote. He said that the coverage formula contained in the original law no longer made any sense: "The formula captures States by reference to literacy tests and low voter registration and turnout in the 1960s and early 1970s. But such tests have been banned nationwide for over 40 years."

But states are now becoming more sophisticated in trying to restrict minority voters — who tend to vote Democratic. Some states simply purge voter lists, on the ground that some on those lists may be illegal immigrants or some may have committed crimes in the past, as Florida attempted to do before the 2012 election. Or they cut back on early voting or prohibit voting on Sundays, when workers would have a better opportunity to cast their ballots. The blatant political motivation behind these laws is obvious. Mike Turzai, the Republican House majority leader in Pennsylvania, described the motivation behind that state's photo ID law: "Voter ID, which is gonna allow Governor Romney to win the state of Pennsylvania. Done."

During the Supreme Court argument in the Shelby County case, Justice Antonin Scalia disputed the significance of the strong congressional vote in favor of the law in 2006. "I think it is attributable, very likely attributable, to a phenomenon that is called perpetuation of racial entitlement.…I don't think there is anything to be gained by any Senator to vote against continuation of this act." Although Scalia displayed a cynical view of why Congress renewed the Voting Rights Act in 2006, the Supreme Court rejected any cynical look at why states are objecting to the extension of the law. The act stood as a barrier to Southern states passing, for example, a voter ID law, even though the evidence is overwhelming that the need for such a law is nonexistent and the true purpose of these laws was to reduce voting by the poor (minorities), who often do not have the necessary government-issued ID.

The idea that the five Republican appointees to the court could strike down the Voting Rights Act (which has the obvious effect of advancing their party's interest) will further undermine the confidence of the people in the fairness of the court, a confidence already at a very low level.

Leon Friedman is a professor of constitutional law at Hofstra University Maurice A. Deane School of Law. He is the editor of and a contributor to The Justices of the United States Supreme Court: Their Lives and Major Opinions (Facts on File 2013).