the surprise election of Republican Scott Brown as US Senator in January (get complete town-level results here) was only the beginning of what promises to be a tumultuous year of politics in Massachusetts. We’ve put together some stats on some of the major factors in statewide politics in the past and future.

party down

Democrats have outnumbered Republicans in Massachusetts for more than 60 years. But as the graph below shows, there has been considerable fluctuation in party strength over that time, and the “unenrolled” (the Bay State’s term for independents) are now on the upswing.

Allegiance to the Democrats was still fairly weak at the end of World War II, but the party began to sprint ahead of the GOP in the 1960s, after the election of John F. Kennedy as president. (The party has held both houses of the Legislature since 1958.) The Democrats hit a peak of 47 percent of the electorate in 1986, the year that Gov. Michael Dukakis was elected to a third term and began a presidential campaign based on the “Massachusetts Miracle.” Four years later, after Dukakis lost the White House and the state’s economy suffered a major breakdown, the Republicans won the governorship and unenrolled voters became the largest bloc in the state. In 2008, there was a surge in voter registration, fueled in part by interest in the fight for the presidential nomination between Democrats Hillary Clinton and Barack Obama, but that was also the year that the unenrolled became an absolute majority in Massachusetts.

What of the GOP? It was just shy of 30 percent of the electorate during the Eisenhower administration and has been losing ground ever since, bottoming out at 12 percent in 2008. But Brown’s election this winter suggests that an overwhelming majority of independents are willing to vote Republican.

As the map below shows, Brown did better than the previous Republican to win a statewide race in Massachusetts — Gov. Mitt Romney in 2002 — in most of the state, especially in Plymouth and Worcester counties. What’s unclear is whether this was a surge for Republicanism or merely a backlash of independents against the ruling Democratic Party. If it’s the former, it’s good news for probable Republican gubernatorial nominee Charlie Baker. If the latter, Democrat-turned-independent Tim Cahill may be the principal opposition to Democratic Gov. Deval Patrick this fall.

contributing factors?

When candidates get generous with themselves, they can dwarf the campaign spending by political parties and “special interests.” This happened in 2006, when four of the top 10 contributors to Bay State campaigns in 2006 were people giving to themselves. None of them — gubernatorial candidates Chris Gabrieli, Kerry Healey, and Christy Mihos and lieutenant governor hopeful Deborah Goldberg — were successful. As the chart at right shows, self-contributions were by far the biggest source of campaign cash that year. (Food and liquor interests contributed heavily for and against a referendum to allow more supermarkets to sell alcohol.)

The governor’s race was ultimately won by Patrick (get complete town-level results here), who put a relatively paltry $181,000 — 4 percent of the total money he raised — into his own campaign, compared with Healey personally kicking in $10.3 million, equal to 74 percent of the total money she raised.

Patrick was easily outspent by Healey ($13.2 million to $8.9 million) over the course of the year. But he had a big advantage in individual contributions, raising $7.6 million from 381,157 individuals, while Healey reaped $3.6 million from 162,222 people. As the chart below shows, Patrick also had an edge in luck raising money in the traditional liberal bastions of Boston, Cambridge, Newton, and Brookline. (Healey’s hefty take from Beverly is almost entirely from her self-contribution.)

Sources: Massachusetts Secretary of State’s Office; Massachusetts Office of Campaign and Political Finance; National Institute on Money in State Politics.