If one actually reads what Obama has said and what is at stake, one can see that their positions are entirely different.

McCain is helping the oil companies to use high oil prices to blackmail the voters into allowing them to have whatever they want. McCain is saying that allowing the oil companies to have whatever they want will decrease the price of oil. This is a lie, and it is not at all what Obama is saying or trying to do.

Obama is not saying that increasing offshore oil drilling will reduce the price of gas. He is not saying that he is in favor of increasing offshore oil drilling. He is not advocating that we give the oil companies whatever they want.

He is saying that there is a bill before the Senate that he thinks has a pretty good chance of getting passed that would help to make the oil companies irrelevant. He is saying that the reason it has a good chance to get passed is because, although it contains elements that will ultimately make oil companies irrelevant, it also contains some short term incentives for senate members who are beholden to oil interests to vote for it anyway.

These are two entirely different things.