Republican strategists who monitor media activity in Massachusetts say the Democratic Senatorial Campaign Committee has purchased TV time, starting tomorrow, to help Rep. Edward J. Markey in the special election for Senate. Markey — who just a few days ago started running a TV spot attacking GOP nominee Gabriel Gomez on abortion, guns and Social Security — continues to hold a narrow lead in the race, probably somewhere in the mid-single digits. But the margin has made Democrats nervous enough that they now appear prepared to throw their considerable weight behind their party’s nominee. (more…)