For weeks, the widespread expectation among most campaign journalists has been that the race for the Democratic nomination will, for all practical purposes, come to an end Tuesday night with a victory for Barack Obama.

Given the predictive record of reporters so far this election cycle, that is by itself a good reason to believe that Hillary Rodham Clinton is headed later this evening for a game-changing comeback in Ohio and Texas.

If it happens, we can think of five reasons why.

Several have as much to do with the idiosyncrasies of news media psychology — and the way this influences political story lines — as they do with any tactical brilliance by Clinton’s campaign.

Clinton’s operatives have been complaining for months about Obama’s unreadiness to be commander in chief and a double standard in coverage. Only in recent days have these protests started to get much traction.