Pollster.com: Brown has significant and growing lead

What are we to believe about all of the polling coming out of Massachusetts over the last week?  After all, no one would have predicted even a close race for Scott Brown at the end of December.  Are we to believe that he could ride almost out of nowhere and derail Democratic attempts to replace its “liberal lion,” Ted Kennedy?  According to Pollster.com, that’s the reality, regardless of which polls one chooses to believe:

So what might you believe about these data? You could refuse to cherry pick the polls. That has long been our view here at Pollster.com. Our job is to summarize the trends as best we can, without partisan favor. If you do that, we get a 8.8 point Brown lead.

Perhaps you only trust non-partisan polls. Then the Brown lead is 6.8 points.

Maybe you are a Dem, who doesn’t trust the Republican pollsters. Then Brown leads by 6.5 points.

Or you are a Dem who doesn’t trust the non-partisan pollsters either and who does believe in the leaks from the Coakley campaign. Then Brown’s lead is 3.8 points. (This is the only estimate that includes the leaks.)

Or you are a Rep who trusts GOP and nonpartisan polls only. Then Brown leads by 11.3. (There aren’t enough Rep polls to run a Rep only estimate to parallel the Dem only, but I’d think an 11 point lead would be satisfying enough for Reps.)

There may be other ways to cut these data (IVR vs conventional phone, pollsters you’ve heard of vs ones you haven’t) but it seems quite unlikely that any but the most selective reading of these data can find that the race remains a dead heat. Brown has a lead, as of Sunday night.

Charles Franklin does offer this warning, and the comparison to Douglas Hoffman’s supposed lead in NY-23:

Let’s also recall the NY-23 special election, which was not polling’s finest hour. The last three polls there had Hoffman up by 5, 5 and 17 points. Our final trend estimate based on all the polls had Hoffman up by 5,  41.8 to 36.8.

Polling special elections is hard. Tuesday we’ll see how hard, and who was good and/or lucky.

In this case, though, the turnout models will probably tell the difference.  Toss out the PPP poll, and the trend is still solidly Brown, even among polls with unrealistic turnout models for Democrats that put them at a +22 or a +23.5 advantage.  Toss out the IVR polls, and you still have ARG, PPP, and others showing Brown widening his lead.

Anything can happen; a coming snowstorm could cool enthusiasm for Brown and blunt the big turnout he needs from independents, for instance, although right now that would appear to be more of a danger to Coakley’s diffident voters.  But the broad range of polls all show Brown surging and Coakley stumbling.  We’ll see whether that becomes reality in tomorrow’s definitive poll of Massachusetts voters, and whether the seat belongs to the people or to Washington DC.

Update: Stuart Rothenberg’s now a believer:

While special elections often come down to turnout – and they therefore are more difficult to predict than normal elections – the combination of public and private survey research and anecdotal information now strongly suggests that Republican Scott Brown will defeat Democrat Martha Coakley in tomorrow’s race to fill the remainder of the late-Sen. Edward Kennedy’s seat.

Brown is running extremely well with Independents in the Bay State, and unless Democratic turnout exceeds everyone’s expectations, Brown is headed for a comfortable win. Move from Toss-Up to Lean Takeover.

Not just a win, but “a comfortable win.”