The federal Election Assistance Commission was formed after the disputed 2000 election between George W. Bush and Al Gore and given an innocuous name and a seemingly inoffensive mission: to help state election officials make it easier to vote.

In this ideologically riven election season, it turns out, that is not easy at all.

The election commission is in federal court this month, essentially accused of trying to suppress voter turnout in this November’s election. The Justice Department, its nominal legal counsel, has declined to defend it. Its case instead is being pleaded by one of the nation’s leading advocates of voting restrictions. The agency’s chairman has disavowed its actions.

The quarrel exemplifies how the mere act of voting has become enmeshed in volatile partisan politics. Seventeen states will impose new voting restrictions for November’s presidential election. Many are the object of disputes between those who say they are rooting out voter fraud and those who say the real goal is to keep Democratic-leaning voters from casting ballots.

The lawsuit’s origin is straightforward. The agency’s executive director, Brian D. Newby, had been in his job less than three months in January when he unilaterally reversed a policy that the body’s commissioners, two Democrats and two Republicans, had endorsed since the agency’s creation in 2002: that people registering to vote need offer no proof, beyond swearing an oath, that they are American citizens.