ANNAPOLIS — Maryland residents are worried about the economy and taxes, according to poll results to be released today that show Gov. Martin O'Malley's popularity continuing to slide. Marylanders gave Mr. O'Malley a 37 percent job-approval rating, down two points from January, while 48 percent said they disapprove of the job he's doing, according to the poll conducted by Gonzales Research and Marketing Strategies of Annapolis. Mr. O'Malley's support among Democrats dropped slightly from January, from 52 to 48 percent. The number of independents disapproving of his performance jumped 12 points over the same time, to 51 percent, which carries...