Lt. Gov. Anthony G. Brown released the second television ad of his campaign for the Democratic nomination for governor Monday, sticking with the positive, issues-free approach of his first.

As in the first, Brown’s spot relies heavily on images of his Army career, including a shot of him at the controls of a helicopter. The theme of the ad is that Brown was “raised to serve others, before serving himself.”

The content is general enough that it could have come from either a liberal Democrat or a conservative Republican. Brown promises to make Maryland “fairer” and “safer” without saying how he would go about it.

“And now, he’s ready to lead with a bold plan to build a better Maryland for more Marylanders,” the narrator said. No details are provided in the 30 seconds the ad runs.

With a commanding lead but 40 percent of the Democratic electorate undecided, Brown has every incentive to keep his ads positive as long as he can. That is expected to change when Brown’s well-heeled rival, Attorney General Douglas F. Gansler, begins running ads critical of Brown’s record. So far, Gansler’s only ad is a positive one dealing with his own achievements in public office.

The other Democratic contender, Del. Heather R. Mizeur, has not yet begun running broadcast ads.