Yep. IIRC George W Bush, who is hardly known to be an anti-oil liberal, ultimately ended up agreeing that AGW was a real thing that needed to be dealt with. This was a man who literally gained much of his power from his connections to the oil industry, more so than the majority of AGW-denying Republicans.
There's a point at which the more serious the consequences, the less you can afford to grandstand and tell people what they want to hear. Just as we see every Presidential candidate split into three virtually completely different people at every election - the party's candidate during the primaries, the centrist during the main part of the election, and the establishment figure post-election - we see some politicians, from time to time, feel obliged to split from their base on key issues.
That doesn't always mean they're right. Obama turning from Guantanamo-closer to drone-assassin and whistleblower-hunter overnight seems more to me about preventing himself from having problems with the security services, or possibly fear of being blamed if there's another high profile terror attack, than anything about it being the right thing to do. But seeing people from Thatcher to Bush acknowledge AGW when there was no establishment pressure to do so, and when the consequences of AGW were unlikely to be felt (or, if felt, were unlikely to result in them being blamed) during their regimes is instructive.