FairVote's director Rob Richie tackles that myth with a letter to the NY Times:
The current system does not benefit small-population states, however. While such states have fewer people per electoral vote than big states, there"s a reason for the conventional wisdom that the 2004 election came down to winning two of the big battlegrounds of Pennsylvania, Ohio and Florida.
A gain of 5,000 votes in New Mexico might help swing five electoral votes in your favor. But that exact same vote gain in Florida could swing 25 electoral votes. When weighing where to focus resources, campaigns gravitate to the big swing states.