I am not encouraged with a state-by-state electoral analysis, no matter who the GOP nominee is this year. Ohio is probably gone blue, thanks to the incompetent and corrupt Bob Taft. Michigan might be a possible pickup, but last year they reelected bonehead Canadian socialist Jenny Granholm. Iowa and New Mexico were narrow wins for W. in 2004 and will probably flip back to Rat. Colorado is problematic as is Missouri. Given that voters generally favor the other party after an 8-year presidency, it looks like The Beast or Osama gets sworn in a year from now.
Assuming Romney wins Michigan (+17) but loses all three states you list (Ohio (-20), New Mexico(-5) and Iowa (-7)) and the rest of the map breaks out the same as 2004 that would result in 271 ECVs (286 +17 - 20 -5 -7) for Romney, which is still a win.