2020 presidential election: How recounts happen in battleground states

WASHINGTON -- Three days after Election Day, the race between President Donald Trump and former Vice President Joe Biden is extremely close in some key battleground states, meaning a campaign could demand or a state could automatically trigger a vote recount.

The rules involving election recounts vary from state to state. In some, like Pennsylvania, a recount is automatically triggered if the final margin reaches a certain percentage. In Georgia a certain margin is required in order to request a recount. In other states, like Nevada, no margin is required but there is a deadline for a campaign to request a recount.

Trump's campaign has engaged in a flurry of legal activity to try to improve the Republican president's chances, including a recount in Wisconsin. Since the state pays for recounts of races that are within a quarter of a percentage point, and the margin in Wisconsin is larger, the Trump campaign would have to pay for it.

The last presidential recount, done in 2016, cost Green Party candidate Jill Stein $3.5 million. The Wisconsin recount gave Democrat Hillary Clinton 713 votes while Trump picked up 844, widening his lead by 131 votes.

Electoral research conducted by the Associated Press found there have been 31 statewide recounts since 2000. Three of those changed the outcomes of their elections. The initial margins in those races were 137 votes, 215 votes and 261 votes.

Among all 31 recounts, the largest shift in results was 0.1%, in the 2006 race for Vermont's Auditor of Accounts. This was a low turnout election in which the initial results had one candidate winning by 137 votes. The candidate eventually lost by 102 votes, for a swing of 239 votes.

The average shift in the margin between the top two candidates was 0.019%.

Here's a look at recount laws protocols in battleground states that are critical in the 2020 presidential election:

Georgia

• Automatic recount?: No
• Deadline to request recount: Two business days after county vote certification
• Margin required for requested recount: 0.5%
• Recount completion date: No set deadline

Michigan

• Automatic recount?: Yes, if the difference is 2,000 votes or less
• Deadline to request recount: Within 48 hours after vote canvass
• Margin required for requested recount: None
• Recount completion date: Automatic/requested: No set limit; as soon as possible after certification of results

Nevada

• Automatic recount?: No
• Deadline to request recount: By three working days after statewide vote canvass
• Margin required for requested recount: None
• Recount completion date: Within 10 days of request

North Carolina

• Automatic recount?: No
• Deadline to request recount: Noon of the second business day after the county vote canvass
• Margin required for requested recount: 0.5% or 10,000 votes, whichever is less
• Recount completion date: ASAP after the county canvass; Set by Board of Elections executive director

Pennsylvania

• Automatic recount?: Yes, if within 0.5% or less of the total vote
• Deadline to request recount: Five days after completion of unofficial canvass
• Margin required for requested recount: None
• Recount completion date: Automatic: Three weeks after the election. Requested: No set deadline.

Wisconsin

• Automatic recount?: No
• Deadline to request recount: No later than first business day after state election commission receives last county board of canvassers' statement
• Margin required for requested recount: Less than 1% in a race of more than 4,000 votes
• Recount completion date: Within 13 days of order for recount

The Associated Press contributed to this report.