Secretary of State William Galvin is standing by the state's voting process, the first time universal mail-in voting had been combined with in-person balloting on a primary election day.

"It was a success, I think was a good day for democracy, it was a good day for Massachusetts. Comparative to other states, we did pretty well,' Galvin said of the election, which likely set a new record for the number of ballots cast at over 1.5 million.

Though voting went smoothly for most, some have criticised Galvin's implementation of the new mail-in voting law, which was adopted in the wake of the COVID-19 pandemic.

The legislator who championed the change disagrees.

"We had both within the same town precincts receiving the wrong ballots, town by town receiving the wrong ballots, certain vote-by-mail ballot kits coming without the yellow ballot envelope, which has the affidavit that voters need to sign. The ballot is then rejected without that envelope," Sen. Becca Rausch told GBH News.

Rausch said her office is working to track problems voters encountered and identify where local clerks were not prepared to conduct the new system.

"There were a number of those preparations that did not happen or did not happen to the level of effectiveness and success that needed to happen," Rausch said.

Galvin admitted that allowing both in-person and mail-in voting adds to the burden carried by election administrators like local clerks and poll workers, creating opportunities for error.

"It's inevitable when you're dealing with such a complex operation. When you're giving voters options, when in fact you're making it easier for them, it comes at the expense of doing more administrative work to do that. And it leads to the potential for mistakes," Galvin told GBH News Wednesday.

Some voters were turned away from polling places if they arrived with mailed ballots instead of depositing the ballots in designated drop-off boxes administered by local elections officials and some simply did not reach the drop-off boxes before the 8 p.m. deadline.

"You have to draw the line someplace," Galvin said, adding that a late arrival at a drop-off box is similar to a voter being turned away from a closed polling station.

"I'm sure there'll be some ballots that weren't cast. Not that I don't care, I wish they were counted. We tried everything we could to encourage people to count them. Everything," Galvin said.

Galvin's next task is to finalize Tuesday's results and prepare the general election ballots for November, when even more Massachusetts voters will take part in the new hybrid voting system.