This weekend’s polling numbers by the Star Tribune’s Minnesota Poll that found Barack Obama up by 18 points over John McCain and Al Franken up by 9 points over Norm Coleman turned many heads in the Gopher State, and received harsh critiques by the right-wing blogosphere (as well as the Coleman campaign).

Fair or unfair, the Star Tribune now possesses a reputation in some circles for being biased in favor of Democratic candidates.

Lefty blog Fivethirtyeight.com doesn’t attribute bias in its pollster rankings, but the popular political blog has named the Star Tribune as one of the least reliable pollsters in the country. The Minnesota Poll is ranked 27th out of 32 organizations across the country in terms of ‘pollster introduced error’ – that is, as the website defines it, “Error that results from poor methodology.�?

The truth is, however, that the Minnesota Poll over time has a fairly good track record – at least when comparing its final survey conducted the weekend before the election up against the actual election results.

· In the 2004 presidential contest, the Minnesota Poll had John Kerry leading George W. Bush by 4 points in the Gopher State (October 31 – November 1). Kerry won by 3.5 points.

· In the 2000 presidential election, the Minnesota Poll had Al Gore leading by 5 points over Bush (November 5-6). Gore won by 2.4 points.

· In the 2006 U.S. Senate race, the Minnesota Poll had Amy Klobuchar leading Mark Kennedy by 21 points (November 5-6). Klobuchar won by 20.2 points.

· In the 2002 U.S. Senate race, the Minnesota Poll had Coleman leading by 2 points over Walter Mondale (November 3-4). Coleman won by 2.2 points.

· In the 2000 U.S. Senate race, the Minnesota Poll had Mark Dayton winning by 9 points over Rod Grams (October 31 – November 3). Dayton won by 5.5 points.

· In the 2006 gubernatorial matchup, the Minnesota Poll had Mike Hatch defeating Tim Pawlenty by 3 points (November 5-6). Pawlenty won by 1 point.

· In the 2002 gubernatorial race, the Minnesota Poll had Pawlenty leading by 13 points over Roger Moe (November 3-4). Pawlenty won by 7.9 points. The poll correctly had Tim Penny winning 16 percent of the vote.

That is not to say the Star Tribune’s recent polling results were not a bit eye-opening – the numbers seen by Obama and Franken in the new poll are likely on the outer edge of reality, accounting for the poll’s margin of error, as it captures the recent movement to the Democrats seen across the board as the nation’s economic problems intensify.