WHY ARE PROGRESSIVES NON-VOTERS?

A 2007 Study found that non-voters are more economically liberal, preferring Barack over Mitt Romney 59% to 24%. Marginal voters, those affected by weather or election timing, are liberal. Among the 34 million registered to vote in 2010 midterms, 63.1% were Democrats. Liberals do benefit from high voter turnout, which can also be volatile. So, from this should we assume that liberals are lazy couch potatoes afraid of the rain who vote only when they see a crowd collecting at the polls?