Bachmann and Perry declining Trump invite: biggest mistake of 2012 primary?

[Politico]

The biggest mistake was easily Perry's "Oops" debate gaffe. And probably a handful of other Perry gaffes I cannot think of right away (let's re-invade Iraq? That odd speech he gave in New Hampshire where he seemed like a gay southerner on pain killers?). Without those, Perry may have ended up winning Iowa and carrying that momentum into South Carolina, leading to a well-financed showdown in Florida and beyond.

The biggest post-Perry mistake goes to Gingrich for doubling-down on the Moon Base.

Santorum's biggest mistake was probably doubling-down on anti-contraception.

[Politico]

Romney's biggest mistake was not going scorched-earth on South Carolina.

Yeah, you're right. I don't even like thinking about South Carolina. I wanted the campaign to keep the boot on Gingrich's throat. This whole circus could have been finished in South Carolina. Then again, a lot of South Carolina came down to Newt Gingrich beating up on John King at the start of the last debate before they voted.