Apparently it's a possibility. At the very least such a run would help Dobbs sell a few more books. Whether a Perot-like third party anti-immigration, anti-globalisation, anti-Wall Street crusade will be as appealing in 2012 as it seems right now must be a matter that's open for discussion. Perot wouldn't have been nearly so effective in happier economic times and 2012, one trusts, will bring cheerier economic news than 2009. Nonetheless, there's no point denying that Dobbs represents a set of sentiments that, generally speaking and most of the time, don't get much of a hearing or great respect in Washington.
Still, if one of the most important things in politics is being lucky in your politics, thn Barack Obama must be licking his lips at the thought of Candidate Dobbs. Sure, the President will take his fair share of lumps from Dobbs and he'll lose some Rust-belt voters too. But Dobbs's appeal, should he run, will be heavily concentrated amongst white, non-college educated men. And since that's a much more important constituency for the Republican party than it is for the Democrats then it makes sense for the White House to welcome Dobbs to the festivities and the race.
And what does Dobbs have to lose? Precious little. So he might as well run, not least because doing so will, probably, help shift the points at which debate pivots a few inches closer to his positions. And even by just threatening to run, Dobbs can probably exert a small but discernible gravitational pull on a Republican party that is a) shifting slowly towards his views anyway and that b) would be sensible to try and do whatever it can to keep Dobbs out of the race.