Rep. Ed Markey (D) has opened up a big lead going into Tuesday's Massachusetts special Senate election, according to a new poll.

The UMass-Lowell/Boston Herald poll shows Markey with a 20-point lead on Republican Gabriel Gomez. He leads 56 percent to 36 percent.

For much of the race, Markey has held a single-digit lead, according to most polls.

A Boston Globe poll last week showed Markey opening a double-digit lead, as did a poll from GOP automated pollster Harper Polling. Polls from Gomez's campaign and another GOP pollster showed it remained a competitive race.

But this is the first time a poll has suggested the race is essentially over.

The UMass-Lowell poll also shows Markey's supporters are more committed, with 76 percent of them saying their choice is firm, compared to 67 percent of Gomez voters.

Update 11:22 a.m.: A new Emerson College poll shows Markey up double digits, but with a smaller lead. It's got Markey at 51 percent and Gomez at 41 percent.

Meanwhile, The Fix's Sean Sullivan has a good write-up on the role Scott Brown has (or rather, hasn't) played in the race.