This week over 3000 Republican will gather in Orlando to meet presidential candidates, watch them debate, and then vote in a non-binding straw poll. Last year’s United States Senate campaign in Florida is highly instructive in how useful straw polls can be. Marco Rubio was trailing Charlie Crist in scientifically conducted public opinion polls early in the primary campaign. But several county Republican Executive Committees conducted straw polls of their members which showed overwhelming support for Rubio. County REC’s are composed of the grassroots activists who raise money, knock on doors, and make phone calls for political campaigns. They are...