Partisan Columnists: #1 Coulter, #2 Krugman
Lying in Ponds tries to draw a fundamental distinction between ordinary party preference and excessive partisanship. The presence of an excessive partisan bias transforms journalism into advertising, too distorted and unreliable to be useful in any serious political debate. Political parties are a healthy, essential part of American democracy; excessive partisanship is not. The methods used here are an attempt to quantify only partisanship, and are not intended as a more general guide to the quality of a columnist.
For example, an analysis of columns in 2007 by Ann Coulter shows that she has had 463 negative comments about Democrats, and only 10 positive comments (about a 46:1 ratio). Paul Krugman has had 603 negative comments so far this year about Republicans, and only 31 positive comments (almost a 20:1 ratio). In comments about Republicans, Coulter's positive comments outnumber negative comments by about 2.5 to 1, and Krugman's positive comments about outnumber negative comments by about 3.5 to 1 (see bottom chart, click to enlarge).
According to Lying in Ponds, "A partisan pundit is one whose opinions nearly always break down along party lines. Assuming that it's unlikely that a partisan columnist is actually formulating the party platform, then the partisan columnist's opinions must therefore derive from allegiance to the favored party or hostility to the other party rather than from independent thought. The views of pundits who are excessively partisan cannot be taken seriously, because their ulterior motives or uncontrolled biases are certain to frequently contaminate their judgements."
Conclusion: Don't take Krugman and Coulter too seriously.