Even if that number is accurate, it still wouldn't have been enough. Obama won by 5 million votes. It really wasn't that close. I am not sure where that 3 million number comes from but it's outdated now if you are comparing 2012 to Bush's total in 2004. Bush got 62 million votes in 2004, and Romney got 61 million votes in 2012. There is no reason to think that 1 million people sat home, heck they could be dead or unable to vote by now.
Further, the idea that we lost because some population of conservatives sat on their hands or wasted their vote on vanity candidates is probably nonsense. Most conservatives showed up and voted for Romney. Of people that sat home, most are actually what pollsters call "adults" and they support Obama and populist left policies even more than the "likely voters" that actually turn out. If every "adult" voted, Obama would have won in a landslide instead of the 4 point victory he got.
Remember Virgil Goode? Remember all the supposed conservatives here and elsewhere that were going to vote for him. Remember how we were told that millions of conservatives would walk away from the GOP and vote Constitution Party. Virgil Goode and his Constitution Party got 122,000 votes. That's it. That isn't even .1% of the vote. All the Virgil Goode/Constitution Party BS you saw people posting here and they actually got 70k LESS votes than in 2008.
The one area we are blowing elections most clearly is on the statewide Senate level. Nominating clowns like Akin, Angle, O'Donnell, etc, doesn't accomplish anything other than give the Democrats more 6 year Senate terms. That is 3 Senate seats right there we could have denied the Democrat Party and instead we threw them away on idiotic nominees who weren't even the kind of people that have a long term political leadership role worth building around. I mean come on, Democrats spent 1.5 million helping Akin win because they knew he had foot and mouth disease and would implode. Akin is the kind of guy who is fine for a very socially conservative district, but NOT a good nominee for a statewide office. We need to vote smarter and ignore the terrible advice of boneheads like Mike Huckabee.
While I disagree with your assessment regarding total votes (only needed a small percentage of that in key swing states), your statewide elections comment was SPOT ON.
Here are the totals I found:
The total we have is 62,615,406 votes (51%) for President Obama, with 332 electoral votes; and 59,142,004 (48%) votes for Mitt Romney, with 206 electoral votes. Barack Obama thus got 3,473,402 votes more than Romney.
One must also remember that the swing states of Florida and Ohio would have made certain that Romney would have won.
http://www.rushlimbaugh.com/daily/2012/11/08/why_did_three_million_republicans_stay_home