After Clinton’s 10-point, er… 9.5-point… if you go by delegates, 8-point win in Pennsylvania, people are asking why Obama can’t close the deal. He’s the leader, right? The “presumptive candidate”? Certainly, presumptive candidates aren’t supposed to lose, that’s a no brainer. But how big a win should we expect from the presumptive candidate? For comparison we can look at how John McCain has done since he wrapped up the Republican nomination on March 4. On that night, he won all four states: Ohio (60%), Rhode Island (65), Texas (51… as many of his would-be voters were busy voting for Hillary), and Vermont (72). Only two states have had Republican primaries since then: he won Mississippi on March 11 with 79%, and Pennsylvania last week with 73%. So let’s call 70% the breakeven point–above it and you’re fine, below it and people are talking. Of course, if Obama was getting 70% or more now, the race really would be over.