For Mitt Romney, the magic number is $158 million. That's how much he'll have to outraise President Barack Obama over the last four months of the campaign to surpass the president, the record holder for campaign fundraising.

Obama's advantage has been lost in media reports highighting the Republican nominee's $106 million June haul. Even Obama's campaign, including the president himself, has downplayed its financial advantage when it warns of being outspent by Romney and the Republican National Committee. For that to happen, Romney would have to best Obama by $39.5 million a month for ...