There are 192,133 new registered voters in Massachusetts since the last presidential election, with three of the state’s 14 counties responsible for more than half of the increase.

As of Oct. 19, 2016, 4,534,974 people are registered to vote in Massachusetts, according to data from Secretary of State William Galvin’s office. The total represents an increase of 4.42 percent since October 2012, when more than 4.3 million voters were registered.

Statewide, around 54 percent of voters are registered as unenrolled, with 34.18 percent registered as Democrats and 10.68 percent as Republicans. Barnstable County has the highest proportion of Republicans, at 15.1 percent, followed by Nantucket (13.79 percent) and Plymouth (13.33 percent) counties.

Suffolk is the most heavily Democratic county at 51.59 percent, followed by Dukes at 37.4 percent and Hampshire at 37.31 percent.

Middlesex County has the highest number of registered voters of any county, at nearly 1.4 million. The state’s most populous county, stretching from the small town of Ashby in its northwest corner down to Cambridge, Middlesex is also home to the largest total increase in voters since 2012, with 55,229 new registrations.

In Suffolk County, there are 31,525 more registered voters compared to October 2012, with registration up by 25,418 in Essex County. Berkshire County had the smallest increase, rising 131 voters to 90,723.
While Democrats continue to hold clear enrollment advantages over Republicans, Republicans outnumber Democrats in at least 13 of its 351 communities.

The total voter enrollment figures also confirm the demise of the United Independent Party’s status as a “major” political party in Massachusetts.

The Green-Rainbow Party in 2014 regained official party status after fielding statewide candidates for secretary of state, auditor and treasurer who cleared the 3 percent threshold.

But with just 5,799 voters -- or 0.13 percent of the state electorate -- in their ranks, the Green-Rainbow Party could also go the way of the UIP after the 2016 election.

Though it is the only party whose presidential ticket this year is topped by a Massachusetts resident -- Dr. Jill Stein of Lexington -- the ranks of the Green-Rainbow Party fell sharply since 2012, dropping about 11 percent from 6,507 people.

The Libertarian party, whose ticket includes former Gov. William Weld as its vice presidential nominee, is one of 25 political designations under which Massachusetts voters can enroll. A total of 17,269 voters are registered with the various designations, which include the America First Party, Pirate Party and Socialist Party.