When the Nebraska Legislature voted 38 to 6 this year to allow people convicted of felonies to cast a ballot immediately after completing their sentences, it was a moment of bipartisan unity.

That moment did not last.

Just before the measure was set to take effect last month, the state’s Republican attorney general, Mike Hilgers, issued a written opinion that the law was unconstitutional. He did not stop there. Mr. Hilgers added that a law on the books since 2005, allowing felons to vote two years after finishing their sentences, was also based on a flawed interpretation of the Nebraska Constitution.

In the weeks since, people convicted of crimes and election administrators have been caught in legal limbo. Had thousands of former criminals been wrongly allowed to vote for 19 years, as the attorney general argued, or were potential new voters being unfairly blocked from registering this year, as supporters of the new law claimed?

Hastily scheduled arguments in front of the Nebraska Supreme Court on Wednesday are the best hope of settling those questions before Election Day, when Nebraska’s vote could carry special import because of the way the state splits its Electoral College votes by congressional district.

“I am hopeful that the Nebraska Supreme Court will quickly issue a decision prior to the November general election,” Secretary of State Bob Evnen, a Republican who last month instructed county election officials to stop registering people convicted of felonies who had not been pardoned, said in a statement. “We will follow whatever direction the court gives us regarding felon registrations.”