BOSTON -- With people like U.S. Rep. Joseph Kennedy III pushing for a universal vote-by-mail option for the 2020 elections, Secretary of State William Galvin sees one issue with mail voting being how to decide which ballot to mail to unenrolled voters in primary elections.

"We are continuing to explore all options for this year’s elections and look for ways to expand access to mail-in ballots. There are some issues that would need to be addressed with any proposal to mail voters ballots unsolicited, including how to determine which party ballot an unenrolled voter would receive for the State Primary," a spokeswoman for Galvin said Monday morning.

Galvin also remains "committed" to preserving an in-person voting option for voters who move frequently or do not have a traditional address to receive mail, and voters with disabilities who may wish to mark their ballot independently.

"We are continuing to explore all options for this year’s elections and look for ways to expand access to mail-in ballots. There are some issues that would need to be addressed with any proposal to mail voters ballots unsolicited, including how to determine which party ballot an unenrolled voter would receive for the State Primary," said spokeswoman Deb O'Malley.

Kennedy wrote a letter to all legislators over the weekend urging them to follow the lead of some other states and pass a vote-by-mail law immediately so that voters don't have to choose between voting and their health.

O'Malley noted that Galvin has advocated for the expansion of early voting by mail, which is available through June 30 as a form of "no excuse" absentee voting in special legislative and other local elections, and is an option for November as well. Under that system, however, voters do not automatically have ballots sent to their homes.