California rejected 100K mail-in ballots because of mistakes
FILE - In this Wednesday, Nov. 12, 2014, file photo, Lydia Harris, a temporary worker at the Sacramento Registrar of Voters, looks over a mail-in ballot before it is sent to be counted in Sacramento, Calif. Over 100,000 mail-in ballots were rejected by election officials in California's March 2020 presidential primary, highlighting a glaring gap in the effort to ensure every vote is counted as a national dispute rages over the integrity of vote-by-mail elections. (AP Photo/Rich Pedroncelli, File)

FILE - In this Wednesday, Nov. 12, 2014, file photo, Lydia Harris, a temporary worker at the Sacramento Registrar of Voters, looks over a mail-in ballot before it is sent to be counted in Sacramento, Calif. Over 100,000 mail-in ballots were rejected by election officials in California's March 2020 presidential primary, highlighting a glaring gap in the effort to ensure every vote is counted as a national dispute rages over the integrity of vote-by-mail elections. (AP Photo/Rich Pedroncelli, File)

Jul. 13, 2020 11:54 AM EDT
FILE - In this Oct. 22, 2018, file photo, mail-in ballots are placed in bins to be processed after arriving at the Sacramento County Registrar of Voters in Sacramento, Calif. Over 100,000 mail-in ballots were rejected by election officials in California's March 2020 presidential primary, highlighting a glaring gap in the effort to ensure every vote is counted as a national dispute rages over the integrity of vote-by-mail elections. (AP Photo/Rich Pedroncelli, File)

FILE - In this Oct. 22, 2018, file photo, mail-in ballots are placed in bins to be processed after arriving at the Sacramento County Registrar of Voters in Sacramento, Calif. Over 100,000 mail-in ballots were rejected by election officials in California's March 2020 presidential primary, highlighting a glaring gap in the effort to ensure every vote is counted as a national dispute rages over the integrity of vote-by-mail elections. (AP Photo/Rich Pedroncelli, File)

Jul. 13, 2020 11:54 AM EDT
FILE - This Friday, June 10, 2016 file photo shows a mail-in ballot yet to be counted at the Sacramento County Registrar of Voters office, in Sacramento, Calif. Over 100,000 mail-in ballots were rejected by election officials in California's March 2020 presidential primary, highlighting a glaring gap in the effort to ensure every vote is counted as a national dispute rages over the integrity of vote-by-mail elections. (AP Photo/Rich Pedroncelli, File)

FILE - This Friday, June 10, 2016 file photo shows a mail-in ballot yet to be counted at the Sacramento County Registrar of Voters office, in Sacramento, Calif. Over 100,000 mail-in ballots were rejected by election officials in California's March 2020 presidential primary, highlighting a glaring gap in the effort to ensure every vote is counted as a national dispute rages over the integrity of vote-by-mail elections. (AP Photo/Rich Pedroncelli, File)

Jul. 13, 2020 11:52 AM EDT
FILE - In this Tuesday, Oct. 28, 2008, file photo, mailed-in ballots are sorted and bundled, ready for counting at the Los Angeles County Registrar-Recorder's office in Norwalk, Calif. Over 100,000 mail-in ballots were rejected by election officials in California's March 2020 presidential primary, highlighting a glaring gap in the effort to ensure every vote is counted as a national dispute rages over the integrity of vote-by-mail elections. (AP Photo/Reed Saxon, File)

FILE - In this Tuesday, Oct. 28, 2008, file photo, mailed-in ballots are sorted and bundled, ready for counting at the Los Angeles County Registrar-Recorder's office in Norwalk, Calif. Over 100,000 mail-in ballots were rejected by election officials in California's March 2020 presidential primary, highlighting a glaring gap in the effort to ensure every vote is counted as a national dispute rages over the integrity of vote-by-mail elections. (AP Photo/Reed Saxon, File)

Jul. 13, 2020 11:53 AM EDT
FILE - This Nov. 4, 2016, file photo shows mail-in ballots being sorted at the Santa Clara County Registrar of Voters in San Jose, Calif. Over 100,000 mail-in ballots were rejected by election officials in California's March 2020 presidential primary, highlighting a glaring gap in the effort to ensure every vote is counted as a national dispute rages over the integrity of vote-by-mail elections. (AP Photo/Marcio Jose Sanchez, File)

FILE - This Nov. 4, 2016, file photo shows mail-in ballots being sorted at the Santa Clara County Registrar of Voters in San Jose, Calif. Over 100,000 mail-in ballots were rejected by election officials in California's March 2020 presidential primary, highlighting a glaring gap in the effort to ensure every vote is counted as a national dispute rages over the integrity of vote-by-mail elections. (AP Photo/Marcio Jose Sanchez, File)

Jul. 13, 2020 11:53 AM EDT