In the end, even the Fairfax County judge deciding a last-minute lawsuit over the rights of poll watchers on Election Day wasn’t sure what the parties were fighting over.

So Judge Dennis J. Smith declined late Friday night to issue an injunction that local Democrats had sought to address what they claimed was an illegal attempt by Republicans to limit party observers — and possibly votes — in Virginia’s biggest Democratic stronghold.

The decision came two days after the Fairfax County Democratic Committee filed a lawsuit against state and local election officials over what the committee says are new instructions being given to poll workers that election observers should not be allowed to move around or talk to voters inside polling places.

In the past, the Democrats say, no such restrictions have existed. The observers — often lawyers — couldn’t say anything about how voters should cast their ballots, but they could speak with them about their rights, and they wanted a judge to order that this election should be the same.

But in five hours of arguments and testimony Friday, the biggest disagreement wasn’t over whether such restrictions are lawful; it was over whether election officials were issuing such instructions. Witnesses for the Fairfax Democrats testified that they had observed training in which poll workers were told to categorically restrict party observers from interacting with voters. County election officials who administer the training testified that the Democrats’ witnesses were wrong and no such instruction was given.

“I’ve never said, ‘You can’t talk to someone when you’re a poll watcher,’ ” said Judy Flaig, the county’s election manager.

Given Virginia’s new voter identification law and its status as a presidential battleground state, the stakes are high for Fairfax Democrats. The blue-leaning county is the commonwealth’s most populous jurisdiction as well as its largest source of potential Democratic votes.

Among other things, the Democrats argued that restricting observers would mean they wouldn’t be allowed to advise voters who lack proper identification that they can go home and get it. Nor would they be able to intervene when voters are improperly issued provisional ballots, which don’t always end up being counted.

Even after election officials testified that observers won’t be categorically restricted, the Democrats’ lawyer, John Farrell, continued to argue for an order that would have forced officials to send last-minute instructions to poll workers saying as much.

Smith declined to issue such an order, in part because he wasn’t convinced it was necessary, he said. But he added that he would be available all day Election Day to revisit the matter if party observers report being gagged.

After the hearing, both sides claimed victory.

“We got an admission from the [county general] registrar that our poll watchers can’t be restricted from talking to voters,” Farrell said. “That’s all we wanted.”