Who are the only Republicans you recall winning in Mass? Romney circa 90's when he was a "democrat-lite" and Scott Brown, a "democrat-lite".
Romney was elected Governor of MA in 2002. And the same Scott Brown who won in 2010 got beaten solidly by the extremist Elizabeth Warren in November. Both Romney and Brown won by defeating very weak female candidates. In a state where only 11% of registered voters are Republican, no one was going to defeat the Dem yesterday, despite him having sat in the House for 37 years with nothing to show for it. As VB said, if the GOP had nominated a Tea Party conservative, it would have been a 20-25 point Markey win, rather than a 10 point win. It was over before it started.