How hard will it be to vote during the coronavirus? It depends on where you live.

If you’re a Pennsylvanian who wants to vote by mail this year, you can — but make sure your ballot arrives by 8 p.m. on Election Day.

If you’re in New Jersey, you have more time. Your ballot will be counted as long as it’s postmarked by Election Day and arrives within 48 hours of the polls closing.

Across Pennsylvania’s northern border in Erie County, N.Y. (home to Buffalo), some polling places open more than a week before Election Day and are scheduled to be available over two weekends, for convenience. In Erie County, Pa., a few miles south, voting early is less flexible. You have to do it with an absentee ballot at the county election office. Weekend hours aren’t certain. (The same goes throughout Pennsylvania.)

And if you live in Allegheny County, you’ll automatically get a vote-by-mail application sent to your home. Elsewhere in Pennsylvania, you have to request one.

» READ MORE: Voting by mail is a safe option during coronavirus. Here’s what you need to know about absentee ballots in Pennsylvania and New Jersey.

As states scramble to adapt elections for the coronavirus pandemic, the rules vary widely, each set by seemingly small bureaucratic decisions that together determine how easy or hard it is to vote — and how many people do or don’t.

Those rules are now subject to a growing legal and political battle across the country, especially in closely divided states like Pennsylvania, where tiny differences could influence who wins its 20 electoral votes and, ultimately, the White House.

Democrats in Congress are pressing for national standards to impose early voting nationwide and ease mail-in voting. After the U.S. Supreme Court ruled that ballots in Wisconsin’s April 7 primary had to be counted if they were postmarked — not received — by that date, some Democrats now argue that standard should apply to all states, including Pennsylvania, and have brought a lawsuit to force the change in Arizona, another battleground.

The Republican National Committee, meanwhile, has set aside $10 million for legal battles against efforts to make it easier to vote, arguing that looser laws could lead to fraud (though studies show election fraud is rare).

The fight — in Congress, courthouses, and legislatures — is now one of the central battles of the presidential race.

“Now is the time to be thinking about what voting should look like in November,” said Rick Hasen, an election law expert at the University of California, Irvine.

As each state decides how to do that, key questions include:

Much could depend on which counties can afford to pay the postage for mail-in ballots or buy the machines needed to process votes — and on localized politics. In states that have long relied on mail voting, every registered voter automatically gets an absentee ballot. In Pennsylvania, state law requires people to apply for them.

In Pennsylvania, you can request an absentee ballot online. New Jersey requires a paper form.

Pennsylvania has a system to track a mail ballot’s status online. New Jersey doesn’t.

New Jersey provides prepaid postage to voters, while Pennsylvania counties mostly don’t (though Philadelphia will this primary).

Elections are run by counties, but they follow highly specific laws set at the state level. In Pennsylvania, that means changes have to clear both the GOP-led legislature and Gov. Tom Wolf, a Democrat.

And given the partisan divide over voting rules, changes for November could be hard to enact.

Democrats, and some Republicans, have argued that during a pandemic, states should do all they can to make voting easier, and provide options — including early voting (which could thin lines at the polls), voting by mail, and secure drop boxes where people can leave absentee ballots.

“This is an attempt at making sure that elections that are run at the local level recognize the pandemic that we are in,” Sen. Chris Coons (D., Del.) said of the national legislation. “This really shouldn’t be a partisan issue. We shouldn’t be forcing people to put their health at risk to vote.”

Philadelphia’s top elections official, Lisa Deeley, called Monday for a change in state law to allow ballots to count if postmarked by an election day and received up to seven days later.

» ASK US: Do you have a question about the coronavirus and how it affects your health, work and life? Ask our reporters.

While some Republican governors and secretaries of state have supported mail-in voting, the GOP more broadly has long fought efforts to make it easier to vote. Led by President Donald Trump, Republican officials argue that each state should set the rules and that it’s risky to mail ballots to people who didn’t request them.

“The overhaul would vastly expand opportunities for fraud and weaken confidence in our elections, but all Washington Democrats see is a potential benefit for their party,” Republican National Committee Chairwoman Ronna McDaniel wrote this month in a Fox News column.

In Pennsylvania, elections officials were already implementing new voting machines and a vast expansion of absentee voting.

As Pennsylvania prepares for its June 2 primary, some counties are hitting bottlenecks: Social distancing measures mean elections staff are working staggered shifts or remotely, and the specialized computers they use don’t always fit within existing office space.

» READ MORE: Pennsylvania House unanimously backs proposal to delay the 2020 primary due to the coronavirus

Delaware County has fallen behind in processing absentee ballots. More than one-third of Philadelphia’s mail ballot requests had not been processed as of April 15, which a city official attributed to COVID-19 precautions.

To remove the logistical hurdles around in-person voting, a number of county elections officials in Pennsylvania are calling for the state to conduct its primary entirely by mail, along with allowing earlier counting of absentee ballots.

If ballots were automatically mailed statewide, proponents argue, it would eliminate one step for voters and free short-staffed offices from having to process requests. In Wisconsin, officials couldn’t keep up and thousands of absentee ballots didn’t reach voters in time — forcing many to stand for hours in lines at the polls.

» READ MORE: Despite coronavirus, Wisconsin is holding an election Tuesday. It could hold lessons for Pa. and N.J.

Unlike many other states, Pennsylvania officials can’t begin reviewing absentee ballots until Election Day, potentially delaying the count. UC Irvine’s Hasen warned that if counting drags and the lead shifts, it could undermine faith in the results.

» READ MORE: How does a Republican lead on election night and still lose Pennsylvania? It’s called the ‘blue shift.’

With Pennsylvania elections officials already short of money, changing to all-mail elections would require investments, along with massive public education campaigns.

Congress has approved $400 million for pandemic-related election costs this year, but Democrats say at least $2 billion more is needed.

Voting rights advocates worry that politics could stymie reforms.

“It frustrates me that voting rights are a partisan fight,” said Suzanne Almeida, acting executive director of Common Cause Pennsylvania.