One important assumption for President Obama’s reelection now seems in jeopardy: His predicted fundraising advantage has not yet materialized. While the reporting is not complete, it appears that Obama’s campaign fundraising and Mitt Romney’s are about on par. Moreover, despite Romney’s expensive primary campaign, his campaign cash position is only slightly less robust than the president’s.

The other component of campaign funds — the super PACs — are more opaque. But, by several accounts, the PAC supporting Romney and led by Karl Rove has a significant money advantage so far over the one backing Obama.

Here’s why this matters: There is no modern precedent for an incumbent president to win reelection without spending significantly more than the challenger. Obama faces several strategic imperatives: Build his positives, build his grassroots army, define his opponent negatively before he knows what hit him. (This is precisely what Bill Clinton did to Bob Dole, and what George W. Bush did to John Kerry.) Fundraising constraints translate into strategic limitations, and that is something the Obama campaign cannot afford.