Where has everyone been getting this 40 million Americans that gamble online from? I decided to take a look at some numbers to try and see if it's a reasonable estimate. According to the 2000 Census, there about 281 million people in America. Let's make some assumptions that will make calculations a little easier.
- People from 0-15 years old aren't gambling online. Yes, I know of teens that are playing online poker and such, but only the 18 and 19 year olds can vote.
- People over 65 years old by and large aren't connected to the internet, let along gambling. Again there are outliers in every subset, but they comprise an insignificant portion of the online gambling world.
- The online gambling community tends to be skewed heavily towards males. I will work on an assumption that of all possible women in the age demo from 15-65 that 5% gamble online which is an overly generous estimate.
In the 15-65 demographic there were 186,176,778 people. Take that and halve it to give you the approximate male population and add 5% of that halved figure to give you approximately how many females are gambling online.
After doing that, you're left with about 97m possible people who will be gambling online. Of that, some are estimating that 40m are actively wagering? Almost 50% of the target market? 40m seems like a very high estimate to me.
When you get a more realistic number and then disburse them around the country into congressional districts and such, assuming even full turnout from all gamblers (which we know isn't the case), I'm still not convinced that the gamblers had much impact.
arty: 
