The Democratic Party has a new challenger to Rep. Andy Harris in Maryland’s 1st Congressional District, after voter fraud allegations ended the previous candidate’s bid, but the odds of his beating the incumbent are slim.  The party had scrambled for a replacement since its primary winner Wendy Rosen had to drop out of the race on Sept. 10, after confirming reports that she had voted in two different states in more than one election. Now, after a week-long search, the party has thrown its support behind John LaFerla, the 63-year-old gynecologist from Chestertown, who had lost in the primary to Rosen by just 57 votes.