Map: Here's how Mass. has voted in every presidential election since 1972

There’s a reason why Massachusetts is a go-to for pundits when they talk about “blue states.” It's one of the most reliable Democratic Party pickups each presidential election cycle. Since 1972, President Reagan has been the only Republican to crack the code and carry the state.

The map above shows how every community in the state has voted in the previous 14 elections. Why 14? Because that's the election data the Secretary of State has available online. If you're a data nerd or a geek for politics — or, god help your social life, both — that link is an absolute treasure trove of information.

Cycling through the years, there are some lessons you can learn.

Despite its reputation as a deep blue state, Massachusetts has long-standing Republican strongholds. You can see persistent red alcoves in some parts of Hampden County; swaths of Worcester County; along the New Hampshire border in northern Middlesex County; and more recently pockets of red in Bristol, Essex and Plymouth counties.

In some years, especially in the '70s and early '80s, those "pockets" were actually "most of Massachusetts." But geography doesn't get a vote; people do. Despite Republicans carrying town after town in 1972 and 1976, Democrats have held Boston and Springfield in every election, and Worcester in all but one.

It's hard to offset the Democratic gains in the commonwealth's three largest cities. Reagan managed it twice: In 1980 he did so with a plurality but not a majority of the state's vote, and in 1984 he was even able to pip Worcester into his column as he picked up 49 out of the 50 states (you get an imaginary cookie if you remember which state went the other way in 1984).

Another lesson is municipalities are not monoliths: Even sapphire blue communities have large Republican minorities in these elections, and vice versa. If Ross Perot didn't exist, this map would show a sea of purple in lots of places. Alas, for your map maker, a third-party candidate means a third color, which hopelessly complicates the red-purple-blue spectrum politicos know so well.

There's just one community that has voted for the Republican in every election since 1972: Small but stalwart Granville. It's the town just west of Southwick, which is the one on the map that takes a little bite out of Connecticut.

Go one town farther west and you're in reliably Republican Tolland, which had the only Republican-Democratic tie on record in these 13 elections. Voters there were split 75-to-75 between President Clinton and Republican Sen. Bob Dole in 1996.

Tolland was also one of 13 communities to opt for Perot in 1992. None of those 13 decided to stick with him or his new Reform Party in 1996, though. Nor did Brimfield, which cast a tie between Perot and Clinton in 1992.