My girlfriend has been REAL into it this season for some reason so while I hate to admit it, I watched too and am pretty up on the subject.
Lambert and Allen were less than one million votes apart in the semi-final (out of 80 million votes), with Gokey coming in third.
For those that didn't watch...(compared to Lambert at least) Allen and Gokey are somewhat similar in look and style. Two average height, semi-soulful white guys with brown hair that is pointy in the front. They were more similar to each other in song choice than either one was to Lambert.
Even if you didn't think they were similar...when you contrast that with a 6'1" gay man with a crazy hairdo, and black eyeliner and fingernails who sings mostly rock, you start to realize that one of these things are not like the others.
I'm not suggesting an opinion or judgment on the looks, styles, or sexual preferences of any of the three; but when Lambert and Allen were that close in the semi and you tack on a couple dozen more million votes in the final you can do the math for yourself on where most of Gokey's votes went.
True, that many of Gokey's fans may have not voted at all in the final, but even if he only carried 5% of the semi-final vote and only 1/4 of his voters switched to Allen it would have been enough, and it was probably many more than that...
AT&T may have helped make it a stronger win for Allen but he still would have won. Its not hard math.