Jay Cost presents a pretty solid case that the Republican field already is very strong, but I'm not quite convinced, and it has less to do with the character or records of the candidates than with the messages they are running with.
Don't get me wrong. I believe that Democrats who are still telling themselves that Obama is unbeatable are either delusional, or just whistling past the graveyard. Any basically competent Republican will, at a minimum, make this a real race.
What concerns me is the whole "this won't be easy" message. Pawlenty, in particular, seems to want to make "suck it up, kids" his central theme; to make green-eyeshade scolding the mark of true leadership. That sounds to me a lot like Walter Mondale's 1984 message ("He won't tell you that. I just did.") Maybe it's a Minnesota thing. I just don't think that people get enthused by messages like that - even in the current political climate where most people basically agree with the fiscal assessment.
In other words, the message can't be "we can beat this thing if we all sacrifice." It needs to be more along the lines of "we have to unleash the people from an over-reaching government that has grown far too large under Barack Obama."
It might seem like a subtle difference, but it isn't. "Telling hard truths" is a loser message. The people know budgets have to be cut. We need to talk about the great results we will get from that - and the great result is not that the budget will be balanced. No matter how much people agree on the importance of a balanced budget, that's not, and shouldn't be, the highest goal. Nobody votes for a President to balance the budget. That is just a steppingstone - a means to an end.
And the end is that America will be stronger, freer and more prosperous.
This argument has two added benefits. First, it makes the balanced budget simply one of the assumptions; a given. It's not our goal in itself, but it is a necessary step towards what we all agree upon. Therefore (second benefit,) anybody who stands in the way of balancing the budget is against America's strength, freedom and prosperity.