“All types of conniving methods are still being used to prevent Negroes from becoming registered voters,” Dr. King asserted during his 1957 Give Us the Ballot remarks at the Prayer Pilgrimage for Freedom in Washington.

“The denial of this sacred right is a tragic betrayal of the highest mandates of our democratic tradition.”

As we have been forced to re-learn during recent elections, Dr. King’s demand that America fulfill her democratic aspirations remains acutely relevant today, more than five decades after he voiced that prophetic challenge.

Consider the arc of our history during the last 50 years.

Responding to widespread assaults upon our fundamental democratic rights, Congress has acted to combat discrimination through the 1965 Voting Rights Act, overwhelmingly reauthorized in 2006; by the National Voter Registration Act of 1993, establishing fair and uniform standards for voter registration; and, following the contested 2000 presidential election, by the Help America Vote Act of 2002.

Yet, despite these bipartisan congressional actions, efforts to suppress the voting rights of minorities, our poor, our elderly, students and disabled continue.

In last year’s election campaigns, we fought against unprincipled and un-American voter suppression campaigns. Supported by the Department of Justice and our courts, we prevailed more often than we failed.

Yet it would be tragic to assume that our struggle to preserve and strengthen our voting rights has finally been won.

Currently, two cases that could weaken our democratic legacy are under consideration by the U.S. Supreme Court – and we can expect more to come.

In Shelby County v. Holder, petitioners are challenging the necessity and constitutional viability of Section 5 of the 1965 Voting Rights Act, “the preclearance” provision. They are doing so despite the fact that Congress in its 2006 reauthorization held 21 hearings and reviewed more than 15,000 pages of supporting materials in finding ample evidence of continuing voter discrimination within the affected jurisdictions.

In Arizona v. Inter Tribal Council of Arizona, et al, moreover, the state of Arizona is asking the court to uphold a state law that requires documentary proof of American citizenship in order to register to vote in that jurisdiction.

The National Voter Registration Act requires only a mail-in voter registration form that requires that the applicant attest to his or her citizenship under oath and penalties of perjury.

Those who are challenging the onerous and unnecessary Arizona registration requirement make a compelling argument.

Allowing the states to require additional, conflicting preconditions to voter registration would be in direct contravention to the underlying purpose of the National Voter Registration Act (commonly known as “Motor Voter”).

Congress acted in 1993 to make voter registration as easy and painless as possible because “confusing and often discriminatory state election rules . . . have a direct and damaging effect upon voter participation in federal elections.”

In the legislative history of the National Voter Registration Act, the Congress expressly rejected a proposed amendment that would have authorized the very evidence-of-citizenship requirement that Arizona now demands.

Yet, Arizona asserts that its law is merely seeking to assure that non-citizens should be prevented from voting in that state in an argument that conveniently overlooks a critical fact: There is no evidence that any non-citizen has attempted to register and vote in Arizona.

Arizona’s determined demand for citizenship documents flies in the face of our nation’s democratic traditions and denies the basic American guarantee of universal suffrage upon applicants of every background.

Between 2005 and 2008, more than 30,000 voter registration applications in Arizona were rejected because they did not include the additional “citizenship” documentation demanded by that state. It has been found, moreover, that 90 percent of the rejected applicants to vote in Arizona were born in the United States.

These facts persuaded the Ninth Circuit Court of Appeals to disallow the Arizona “citizenship documents” requirement.

Hopefully, the Supreme Court will agree.

Congressman Elijah Cummings (D) represents Maryland’s Seventh Congressional District in the United States House of Representatives.