(AP) -- The rules of elections are always changing.
In the states and the District of Columbia, lawmakers last year considered more than 2,900 bills dealing with elections and voting, and enacted more than 350, according to a tally by the National Conference of State Legislatures.
The changes include deadlines for registration, pay for election workers and many other details. But the overarching story is that there are simultaneous pushes across the country to make it easier or harder to register and vote.
A look at some of the common issues playing out in the states:
VOTER ID REQUIREMENTS
Thirty-four states require voters to show identification at polling places; several others require IDs of voters the first time they vote. A North Carolina voter ID law is on hold pending the outcome of a lawsuit.
To voters with driver's licenses, the requirements typically are not a big deal. For others — disproportionately the young, old, disabled, poor and minority — gathering the documents for a valid ID can be a barrier to voting. To get a valid government-issued ID, a person may need to go through the process of getting a reissued birth certificate or Social Security card, which can take months.
Voter ID laws have become more common and more restrictive since a 2013 U.S. Supreme Court ruling that overturned a key piece of the Voting Rights Act of 1965. Nine states that had a history of racial discrimination no longer have to submit voting changes to the federal government for review before they become law. All nine of those states now ask voters to show some form of ID at polling places. Some of the ID laws were adopted before the 2013 ruling but had been blocked from taking effect.
The stated reason for voting ID requirements is preventing fraud by voters. It does happen, but not often.
Justin Levitt, a professor at Loyola Law School in Los Angeles, has been trying to track voter impersonation cases that could have been stopped with tougher voter identification requirements. He said he's aware of fewer than 50 incidents over the last two decades, out of more than 1 billion of votes cast in federal elections alone. He said such efforts are rare in part because they aren't likely to swing elections.
"Fraud by voters nets you a few incremental votes," Levitt said. "What's the point?"
The Heritage Foundation keeps a database of election fraud cases of all kinds going back to the 1990s. While the list is not comprehensive, it has fewer than 1,000 incidents over a span of more than two decades, including charges such as vote-buying, where candidates rather than voters were the wrongdoers.
Some recent cases that have gotten attention had nothing to do with IDs.
Terri Lynn Rote of Des Moines, Iowa, pleaded guilty of trying to vote twice by absentee ballot in 2016 and was fined $750. Rote said she wanted an extra vote for then-candidate Donald Trump because she believed the system was rigged against him.
Last year, a Sacramento man, Gustavo Araujo Lerma, was sentenced to nearly four years in prison after being convicted of voting fraud. A judge found the Mexican citizen impersonated an American citizen so he could vote over a period of two decades. At trial, he testified that he was a Trump supporter.
In December, the Democratic governors of Kentucky and New Jersey took action to expand voting to people who have served time after felony convictions, continuing a national trend of restoring rights of people after they are released from prison.
In New Jersey, 80,000 people who have completed prison sentences but remain on parole or probation will be able to vote in elections starting in March under a law passed and signed in December.
In Kentucky, 140,000 people who have completed sentences for non-violent offenses can vote under an executive order signed by in December by newly elected Democratic Gov. Andy Beshear.
People convicted of crimes are disproportionately black men, a demographic with low election participation. The Sentencing Project says that 1 in 13 black adults is ineligible to vote because they're in prison, on parole or probation, or have been convicted of a crime that bars them from voting in their state.
But restored voting rights remain in flux in one important presidential battleground state. In 2018, Florida voters amended the state constitution to allow 500,000 people who have completed sentences for felony convictions to have the right to vote.
The GOP-controlled Legislature last year passed a law creating a caveat: The rights would be restored only to those who had paid all their fines and court costs. To proponents of the change, the idea is that those payments are part of the punishment.
Opponents called it the equivalent of a poll tax and sued. The Florida Supreme Court issued an advisory opinion this past week siding with Republicans and Gov. Ron DeSantis.
A lot of election access battles are over voter registration.
Most states allow voters to sign up online, and several let them register on Election Day. In California, voter registrations are now updated automatically when people interact with the state Department of Motor Vehicles — unless they opt out.
But the practice, which launched in 2018, has been riddled with errors, including people being registered with the wrong party and some non-citizens being added to voter rolls.
At least 16 states have some version of automatic registration, most involving motor vehicle agencies. In other places, pruning of registration lists has become controversial.
Election administrators are supposed to take out the registrations of people who have died or moved out of the jurisdiction -- or in some places, failed to vote in the last several elections.
How it's done is at the heart of legal battles playing out in some states, including Wisconsin and Georgia.
Georgia officials removed 313,000 people from voter rolls last year. Fair Fight Action, a group founded by Stacey Abrams, a Democrat who narrowly lost the 2018 election for governor there, objected.
The group said that 120,000 people were taken off the rolls because they did not respond to postcards that said they had not voted or had other contact with election officials for three years. The state agreed that about 22,000 of those should not have been taken off the list.
But the fight continued regarding the remaining 98,000, with Fair Fight arguing that the state should have followed its new law and sought to remove only people who had no contact with voting officials for five years. In late December, a judge disagreed and found the state could remove voters from the list.
At the same time, a conservative group has taken legal action in a handful of places to try to force voter-roll pruning. The Public Interest Legal Foundation sued Detroit officials in December for not properly maintaining voter lists. It said the rolls there included more than 2,500 deceased people who were born at least 85 years ago -- including one with a listed birth year of 1823.
"Dead people aren't the problem. It's the fact that no one is catching it. What is getting overlooked?" said the group's spokesman, Logan Churchwell.
Churchwell said that when voter registration rolls are sloppy, they can also be vulnerable to hacking and other interference.