It's may not be the first in the nation, but Massachusetts has its own presidential primary in three weeks—with a looming complication.

Voters not enrolled in a political party in Massachusetts can vote in any primary they want, but Secretary of State William Galvin says some voters might have enrolled in a new party by accident.

"The United Independent Party, that has, because of its name, has confused many voters," Galvin said. "Unfortunately they will not be able to vote in the Democratic or Republican primaries unless they change back to independent by Wednesday."

Galvin's office mailed out notices to the 21,000 members of Evan Falchuk's United Independent Party, saying they have to unenroll by this Wednesday if they want to vote for a Democrat, Republican or Green candidate.

Galvin predicts more than 1 million Massachusetts voters could come out March 1.