When going to City Hall to register to vote, the young people of Lawrence often tick off the box next to No Party.
But when they go with their parents to register, they enroll under whatever major political party their families have traditionally supported, said Rafael R. Tejeda, the city’s election coordinator, who noticed the phenomenon.
“At times the parent will declare, ‘In my house we vote Democrat!’” he said with a chuckle.
While avoiding parental disappointment is still very much in vogue, the same cannot be said for strong political party affiliations that have defined past generations. Data from the last two gubernatorial elections and the state primaries in September show more voters in the Boston suburbs are choosing to register as “unenrolled,” the state’s definition for independent voters.
Since 2006, the number of voters registered as unenrolled has increased in 156 of 158 communities across Eastern Massachusetts; the only exceptions were Brookline and Marblehead. In the same period, more people have registered to vote in all but 11 of those communities.
With a 32 percent increase in unenrolled registrations, Milford experienced the highest surge in the region, followed by a 29 percent increase in Billerica, and 28 percent in Hopkinton, according to a Globe analysis of enrollment data for the 158 cities and towns spanning from Salisbury to Boylston to Plymouth, and excluding Boston and Cambridge. The enrollment numbers include both active and inactive voters.
As of August, 55 percent of the region’s 2.4 million voters were registered as unenrolled; 33 percent as Democrats; and 11 percent as Republicans, according to the secretary of state’s office. Both Democrat and Republican enrollment decreased from 2006, while unenrollment increased. In 2006, 35 percent of the region’s 2.2 million voters were registered Democrats; 13 percent Republicans; and 52 percent unenrolled.
The numbers reflect a nationwide trend of voters increasingly registering as independent, and an overall decrease in party membership, said Michael Kryzanek, professor of political science at Bridgewater State University.
“The reputation of the political party machine has certainly come upon hard times,” Kryzanek said in an interview. “In the ’40s and ’50s, people voted ‘the party line.’ They saw their allegiance to a political party as part of their personal identification. This changed with Watergate and other historical events and personalities that moved people away from that allegiance to the political party.”
Political apathy has also played a role in the rise of the unaffiliated, especially amongvoters 45 and younger who feel less comfortable voting in lockstep with a party, with some opting not to vote at all, Kryzanek said.
This echoes a recent study by the Pew Research Center showing that so-called “Millennials,’’ now age 18 to 33, are most likely to identify as politically independent. This has forced major party candidates to go after the unenrolled, changing the way campaigns are run, including those of gubernatorial candidates Charlie Baker and Martha Coakley , Kryzanek said.
“That’s what both the candidates are doing now,” he said. “But it’s a crapshoot when you don’t have that party stability.”
As of August, unenrolled voters outnumbered registered Republicans in all of the 158 communities analyzed, and Democrats in 149. Plympton ranks highest in the region in unenrolled registrations, with 69 percent of its 2,092 registered voters eschewing party affiliation.
A major factor may be the state’s open primary system, which allows unenrolled voters to choose between party ballots without having to officially declare a political affiliation, as was the case in the past, said Brian McNiff, spokesman for the secretary of state’s office.
‘It’s much easier to be unenrolled than it used to be.’
“It’s much easier to be unenrolled than it used to be,” he said. “It used to be you’d take a primary ballot and you were in that party until you leave it. . . Now you can go in and they ask you what ballot do you want; you vote, and you’re still unenrolled.”
To a certain extent, McNiff said, some voters politically aligned with a party will choose to register as unenrolled to try to manipulate outcomes, or to have a say if one party’s races are more hotly contested than the other’s during a primary.
“If you have more action in the Republican primary in your community, or you really don’t like somebody who’s running,’’ McNiff said, unenrolled voters might say, “ ‘Oh, I want to get in on that and vote against that candidate, or vote for that candidate.’
“It used to be you had to register in the party and then unregister yourself,” he said.
There were some bright spots for the two biggest parties: Registrations of Democrats and Republicans still increased in 88 and 42 in the 158 communities, respectively.
Middleton had the highest increase in Republican enrollment in the region, at 20 percent, followed by Milford, with 16 percent. While Democrats still outnumber Republicans in both communities, unenrolled voters represent the majority in both.
According to August enrollment figures, Republicans outnumber Democrats in just eight communities regionwide: Boxford, Cohasset, Dover, Duxbury, Hamilton, Norfolk, Topsfield, and Wenham. Still, in each of those communities, the majority of registered voters are unenrolled.
Brockton had the highest increase in the region for Democratic enrollment, by 24 percent.Lawrence, the bluest community in the region at 56 percent Democrat, saw a jump of 21 percent in that party’s enrollment since 2006.
Tejeda, the election coordinator in Lawrence, said the majority of the city’s residents are of Puerto Rican and Dominican descent, groups that, for the most part, traditionally and fundamentally identify as Democrats.
Lawrence’s 28 percent drop in Republican enrollment since 2006 was second to Brookline’s 35 percent. Brookline was the only community in the region that experienced decreases in every enrollment category. Total voter registration in Brookline dropped by 13 percent from 2006 to August, according to state figures.
Brookline’s town clerk, Patrick J. Ward, said the community’s registration figures are affected by its significant number of transient residents, ranging from young professionals starting first jobs to medical students doing hospital residencies, and undergraduate college students. Moreover, Brookline is not attracting many new voters because there is no room to build housing, he said.
“It’s more the nature of residency in this town; people come in and out all the time,” Ward said
Kryzanek said the days of party-line voting “are pretty much gone.”
“I wouldn’t say [political parties] are on life-support, but they’re not what they were 30, 40, 50, or 100 years ago,” he said. “This is a commentary the unenrolled are making on the traditional form of government: that they are individuals who are able to make up their own minds. . . There’s no doubt in my mind this is a reaction to the old way of party politics. One way of responding to it is not being associated with it.”Katheleen Conti can be reached at email@example.com. Follow her on Twitter @GlobeKConti.