This election year was looking bleak for Democrats in the Senate simply because of how lopsided the playing field is.  Democrats have 23 seats to defend, while the Republicans who only need to defend 10 seats.

But Senate Democrats’ hopes to keep control of the chamber received a huge boost when Maine’s Republican Senator Olympia Snowe made the surprise announcement she would not seek another term.  A win in Maine will be critical for Democrats to make up almost assured losses elsewhere.

Snowe is an historic anomaly in our modern political system. She is a well liked Republican representing what by many measures is a Democratic state. She likely would have won re-election in spite of her party label, because during her decades long history as a public figure she has built a lot of personal good will with voters. People were voting for her and not her party. She is basically a Senate remnant from a different political time. With her personal appeal out of the picture, the Senate seat should revert back to modern political patterns.

Maine has become a state that now strongly favors Democrats. That is why during a huge 2010 Republican wave, Democrats still managed to hold on to both of Maine’s congressional districts.

It is the 12th most Democratic state and 12th most liberal state according to Gallup. It is also the state where President Obama has his 16th highest job approval rating.

In 2008 Obama only won 52.9% of the national popular vote, but he carried Maine with 57.7% of the vote. This made Maine Obama ‘s 11th best performing state. With 2012 being a presidential year, turnout among young voters that lean Democratic should again be high.

Unless there’s a Republican candidate who is incredibly popular, which currently doesn’t appear to exist, or a massive national swing towards the Republican party before November, a Democrat should win this seat.

One aspect of the growing polarization and unification of political parties in America is that elections become more predictable based on demographic trends. Legacy politicians like Snowe who managed over decades to make themselves their own brand could buck this national dynamic. With Snowe and her brand gone, though, what will likely matter most is the party brands.  And in Maine the preferred brand is clearly Democratic.