GEORGETOWN — The U.S. Supreme Court plays a pivotal role in deciding who votes, how citizenship is defined and what democracy is all about. In short, it is central to democracy and its success or failure.

After the Civil War, the court upheld legislation giving black men the right to vote. Although Reconstruction ended in 1877, political reform movements continued. They culminated in the 1890s when poor white farmers and poor black farmers came together to challenge the ruling white elite in states like Georgia, Alabama and North Carolina.

It was at that point that the “best white men” determined to take the vote away from blacks (and eventually poor whites as well). Between 1890 and 1901, Southern legislatures disenfranchised virtually all blacks. The Supreme Court did nothing to interfere.

In fact, the court further sanctioned the denial of civil rights in 1896, when it ruled in Plessy v. Ferguson that race should be the sole basis for allowing access to schools, transportation and public facilities like hotels and restaurants. So although Homer Plessy had just one black great-grandparent out of eight – and passed for white – the court ruled that he had no constitutional right to travel in a “whites-only” car of a Louisiana train.

It took six decades of resistance before blacks could overcome these court-sanctioned denials of equal citizenship rights. The NAACP Legal Defense Fund launched multiple suits, starting in 1915; finally, in 1954, the Supreme Court, in Brown v. Board of Education, ruled that school segregation was unconstitutional.

Meanwhile, black activists continued to spearhead a drive for social justice, culminating in the civil rights movement of the 1950s and ’60s. That movement crested with the Civil Rights Act of 1964, which outlawed employment discrimination against blacks, guaranteed them equal access to schools and all other public accommodations and prohibited discrimination in public places; and enactment of the Voting Rights Act of 1965, which outlawed discriminatory voting practices such as poll taxes and literacy tests. States that had deprived black Americans of voting rights were now subject to federal oversight to make sure that they complied with the law.

Then, in the 21st century, the Supreme Court once more showed how central it could be to the survival of democracy. In the 2013 Shelby ruling, Chief Justice John Roberts wrote that federal oversight of those states that had discriminated against blacks at the polls was no longer needed – because, he wrote, the blatant bias that had made the supervision necessary no longer existed.

However, following Shelby, states like North Carolina engaged in massive redistricting efforts designed to consolidate blacks in some voting districts and give whites a majority in others. The result: In 2014, Democrats won 49 percent of the vote in North Carolina, but were elected to only 33 percent of the seats in the state legislature.

In subsequent cases, federal courts have found North Carolina guilty of both racial and partisan gerrymandering, both of which violate equal voting rights for blacks. Those cases have yet to come before the Supreme Court. But when they do, they will highlight the degree to which the Supreme Court remains central to the future of our democracy.

Statisticians confidently predict that the United States will become a majority non-white country by 2050. Does that mean that in the second half of the 21st century, this non-white majority will have as much say politically as the white minority? What happens if a Supreme Court, with a majority of judges as or more conservative than Chief Justice Roberts, determines that racial or partisan gerrymandering is not a violation of equal voting rights? Do we not then go back to the early 20th century, when federal courts failed to intervene in state policies that took equal voting rights away from blacks?

So the Supreme Court is not removed from the future of democracy, or equal rights. It is at the center of the battle – hence, the importance of who gets appointed to that court for the next generation.