So, overall, his electoral record is 1-2 — or, if you count each state in 2008 as a separate contest, which might not be exactly fair, he’s something like 2-17.
Add last week’s Iowa result, where he underperformed again (and earned exactly six FEWER votes than he earned in 2008), and you have a candidate who just doesn’t seen to be able to deliver on Election Day.
By contrast, Rick Perry famously has never lost an election (but then again, he hasn’t exactly had as tough a row to hoe in Republican-friendly Texas, and barely won re-election for governor in 2006 over an underfunded Democrat). Rick Santorum, running every single time in battles that were uphill or (once) no better than 50-50 shots (i.e. in districts or a state that was not friendly to Republicans), has won four out of five elections, and outperformed other Republicans in his state in almost every case in doing so. (For instance, in 2000 he won PA by four points while GW Bush was losing it by 5; in 2006, even in losing, he lost by less than the GOP candidate for governor that year did.)