Surely there are both bad and good Republican consultants, better and worse messages and tactics. What we need now is a means of determining one from the other. This is the real Democratic and Progressive advantage; the ability to distinguish between what works and what doesn’t using social science experiments.

Beginning with Progressive interest groups more than a decade ago, liberals allied with academic social scientists to study politics the way medical researchers study the effects of drugs. They embraced the core of the scientific method, deploying randomized, controlled experiments to rigorously test the effectiveness of their messages and tactics.

With these experiments, Democrats built – and continue to build – an objective base of knowledge on what works and what doesn’t. Today, the Left is permeated with a culture of testing. Expert opinions are taken as just that; opinions, hypotheses to be tested with experiments.

Why did the Obama campaign invest so heavily in grassroots field offices? Years of randomized-controlled experiments indicated that, for all their expense and difficulty, they gave the highest vote return. Why did they promote strange video pledges to support the president or send “voter report cards” informing Democrats of their voting record and how it compared with their neighbors? Experiments indicated that these are effective at getting out the vote.