Underdog candidate Doug Duncan (D) unexpectedly pulled out of the Maryland governor’s race today, just as his campaign appeared to be on the up tick following months of trailing Democrat Martin O’Malley in the polls and fundraising.

The Montgomery County executive said this afternoon that he had recently been diagnosed with clinical depression and wanted to focus on his health.

Duncan trailed O’Malley in many polls by more than 10 points and in the last campaign financial disclosure from January he had around one-fourth the cash on hand as Baltimore’s mayor. But this past week Duncan held several fundraisers and managed to pick up several endorsements, including the Montgomery County Chamber of Commerce.

The pull out strengthens O’Malley’s run against incumbent governor Robert Ehrlich (R), as he now has no credible primary challengers. A recent Zogby Interactive poll placed O’Malley at 53 percent to Ehrlich’s 39 percent.

Also in the news today, Ehrlich vetoed legislation slated to delay a utilities rate hike for customers of the private utility Baltimore Gas & Electric. The decision was sensitive for Ehrlich since he is running as a “pro-business” candidate but also must appeal to consumers angry about the proposed 72 percent July 1 rate hike.

Ehrlich had been expected to veto the measure, saying that the legislature’s plan does not offer consumer choice because consumers are forced to accept a rate hike deferral.

The Democratic controlled legislature is predicted to override Ehrlich, when it meets tomorrow. The original bill passed by veto proof majorities in both the state House and Senate.