WASHINGTON — Civil rights groups have spent a decade fighting requirements that voters show photo identification, arguing that this discriminates against African-Americans, Hispanics and the poor. This week in a North Carolina courtroom, another group will make its case that such laws are discriminatory: college students.

Joining a challenge to a state law alongside the N.A.A.C.P., the American Civil Liberties Union and the Justice Department, lawyers for seven college students and three voter-registration advocates are making the novel constitutional argument that the law violates the 26th Amendment, which lowered the voting age to 18 from 21. The amendment also declares that the right to vote “shall not be denied or abridged by the United States or any state on account of age.”

There has never been a case like it, and if the students succeed, it will open another front in what has become a highly partisan battle over voting rights.

Over the past decade, Republicans have campaigned to tighten rules for voters, including requirements for photo ID, in the name of preventing fraud. Democrats have countered that the real purpose of those laws is to make voting more difficult for people who are likely to vote Democratic.