About 4,500 Georgia voters prevented their registrations from being canceled after they received warning letters from election officials and phone calls from political groups.

Those voters were originally among the 313,000 names on the state’s cancellation list, but they re-activated their registrations by contacting local election offices, re-registering or voting.

In all, 308,753 voter registrations were removed from the rolls Monday night because they haven't voted since before 2012, they filed change of address forms, or their election mail was returned, according to an updated list provided by the secretary of state's office.

A new state law required election officials to mail notifications to voters at risk of losing their registrations. If voters filled out and signed a postage-paid postcard within 40 days, their registrations weren't canceled.

Outreach efforts also helped reach voters before they were removed from the rolls.

Related: Judge allows Georgia to purge 309K voter registrations overnight

Related: Georgia's strict laws lead to large purge of voters

In Depth: Precinct closures harm voter turnout in Georgia, AJC analysis finds

The secretary of state's office made public the cancellation list in October, and then the Democratic Party of Georgia and the voting rights group Fair Fight Action launched campaigns to contact voters. In addition, four Democratic presidential candidates sent text messages to thousands voters on the list after last month's debate in Atlanta.

Those efforts were designed to reach inactive voters — those whose registrations were in jeopardy under Georgia's "use it or lose it" law because they hadn't voted since 2012. A federal judge is scheduled to hear arguments in a case Thursday in which a voting rights group wants the court to restore the registrations of inactive voters impacted by the law.

There were 117,771 registrations canceled for inactivity, representing 38% of the total. Those voters were declared inactive after three years in which they failed to participate in elections. Then their registrations were voided after they missed the next two general elections.

The rest of the cancellations targeted voters who likely moved from Georgia. They either filed change of address forms, or mail sent to them by election officials was undeliverable.

“There are a lot of reasons a person chooses not to exercise their right to vote. Maybe one of them is that they haven’t found anyone they wanted to vote for,” said Saira Draper, voter protection director for the Democratic Party of Georgia. “It’s somewhat burdensome that an already registered voter then has to re-register to remain on the rolls.”

Related: Democratic candidates text Georgia voters who may be purged

Related: Georgia cancels fewer voter registrations after surge last year

State election officials said voter registration lists need to be regularly maintained to remove voters who have moved or died. It’s unknown how many of the cancellations applied to people who have died.

“Accurate voter rolls are a crucial component of secure and efficient elections,” said Chris Harvey, Georgia’s election director, in a statement earlier this year. “By partnering regularly with stakeholders like the U.S. Postal Service, we’re ensuring that only registered eligible voters are participating in their elections.”

This week’s cancellations eliminated about 4% of the 7.4 million registered voters who were on the state’s voter rolls as of October.

The cancellations roughly reflect the demographics of the state’s registered voters, according to an analysis by The Atlanta Journal-Constitution of voters who provided their race when they originally registered.

About 31% of canceled registrations matched African American voters, and 63% of the removals affected white voters.

Besides the voters who saved their registrations by re-registering or responding to mailed notices, there were 118 people on the initial cancellation list who retained their registrations by voting in last month's local elections, according to state voter history files. Their names didn't appear on the final cancellation list.

Another 293 people who cast ballots in November 2012, recent enough to prevent their cancellation, were included on the original cancellation list because of a data error. State election officials preserved those voters' registrations after APM Reports and The Atlanta Journal-Constitution exposed the issue.