The June 25 special election in Massachusetts to fill the Senate seat vacated by John Kerry‘s appointment as Secretary of State has been moved from “leaning Democrat” to “toss-up,” reflecting the surprising competitiveness of Republican candidate Gabriel Gomez.  The new rating by the non-partisan Cook Report also reflects the unsurprising weakness of Democrat Ed Markey, who has been in Congress more than 30 years.

“Democrats nominated a long-serving member of Congress at a time when Congress is an almost universally unpopular institution,” the Cook Report’s Jennifer Duffy wrote in an analysis cited by the Christian Science Monitor. “It doesn’t help that Markey has not had a competitive race in decades.”

A poll two weeks ago showed Gomez leading among independent voters in Massachusetts, a key factor for any GOP candidate in Massachusetts, where registered Democrats outnumber Republicans nearly 3-to-1. That poll found Markey at 48 percent and Gomez at 41 percent, a single-digit margin. The National Republican Senatorial Committee is hitting Markey with ads highlighting the 18-term congressman’s record on taxes: