Washington, D.C. -- As President Barack Obama and Mitt Romney prepare for their party conventions, their campaigns are trying to invigorate core supporters while reaching out to undecided voters who harbor doubts about the incumbent yet aren't sold on his GOP rival.
In the past week the campaigns have engaged in a vigorous debate over Medicare, pushing aside the economy and jobs.
Romney has charged Obama with running a campaign based on hatred. Obama has renewed a fight over Romney's tax returns. The issue of government spending has blossomed again.
These are the seeds that candidates are planting with fence-sitting voters even as the campaigns try to get backers excited in time for the conventions. Republicans will gather in Florida in a week, and Democrats will be in North Carolina early next month.