At today's price of oil, a rough estimate of the benefit -- not counting environmental costs -- is over $600 billion.
On the other hand, I don't think the good people at the RNC performed a cost-benefit analysis before they took up their cheer.
Will Wilkinson blogs the truth
Democratic politics, in the end, is not about rational deliberation. It is about coalitional signaling. It is about expressive solidarity. It is about identity and emotion.
Translation: politics is about ganging up on those who are different from you.
The people at the RNC want to drill for oil in Alaska because it will upset the environmentalists they despise so much. The environmentalists, similarly, are against drilling out for purely emotional reasons.