"Doubled" is an insignificant statistic. If I get one black person to vote for me, and the next time I get two, I have doubled the result. Who cares? It looks like he was able to get--surprise surprise--about 1 out of 10. And he lost. So, while I don't think I am stupid, I am not moved by this example.
Instead of 95-5, it was 90-10. And that's on roughly 25% of the electorate. If the electorate was 400 people, he gained 5 and Blanco lost 5. That closes a 2.5% gap. How is picking up 2.5% not huge? It's simple arithmetic.
Of course, you have to be within 2.5 points in the first place for it to mean victory, but why dismiss the successful part of the campaign strategy because other parts of a campaign were less successful?