Chillizza puts a plausible floor for Romney electoral vote performance at 191 electoral votes and a ceiling at 292 electoral votes:
Romney would win 292 electoral votes if he replicated the Bush 2004 victory. But New Mexico seems like a very tough place to win — not to mention the fact that he would again need to carry Ohio, Florida, Colorado and Nevada as well as North Carolina and Virginia...
Sen. John McCain (R-Ariz.) won 173 electoral votes in 2008. If Romney carried those same 22 states under the 2012 map, he would win 180 electoral votes. Add Indiana, which McCain lost but which will almost certainly go for Romney in 2012, and the former Massachusetts governor’s electoral floor sits at 191.If Romney fails to collect just 23 of the electoral votes that are part of Romney's best case scenario, then Obama wins. About 101 electoral votes are plausibly in play in this election.
As Colorado Pols notes, it is very hard to imagine a plausible scenario in which Romney wins the Presidency without winning Colorado's 9 electoral votes. We are one of the key swing states in this election. New Mexico have 5 electoral votes, Nevada has 6, Florida has 29, North Carolina has 15, Virginia has 13, Ohio has 18, Pennsylvania has 20, New Hampshire has 4, Iowa has 6, Wisconsin has 10, Michigan has 16, Delaware has 3, and West Virginia has 5.
One recent poll has Obama and Romney tied in Colorado, with 47% each and 6% undecided.