'Trojan Horse' depends upon your point of view on that question. If you believe 'the people' are the Party, then yes, an argument could be made that the President was a 'Trojan Horse', because that depends upon something being 'hidden' from those who received the 'Horse'. But do 'the People' own the Party, or just a small subset of people with power, most of whom are already wealthy? If that's how you view things, then there was nothing 'hidden'. They knew what was acceptable in a candidate, and were fine with either Obama or Clinton in 2008 (and Clinton in 2016).

But Obama did not campaign entirely 'in disguise'. Yes, he used liberal rhetoric, but at the core of the ideas he presented, even in campaigning in 2007 was the same sort of 'socially liberal, fiscally conservative' Democrat the Party machinery is entirely comfortable with. If there was any area in which one might suggest he misled, it was in foreign adventurism, but even there he hedged by saying he was only against 'stupid wars' - without mentioning all sorts of covert drone wars the world over, or his current level of comfort with massive intelligence agency overreach in 'Big Brother'hood.

So I'd say 'Trojan Horse' is the wrong metaphor. He mostly didn't hide who he was. He simply let others project their own hopes for change on him.