Readers write about war-hero candidates, youth voters, and school testing.
His decisive victory in North Carolina shows he can rebound from setbacks, analysts say.
His lead strategist says if McCain were to get 20 percent of these voters he will win.
His lead in North Carolina is dwindling, but he's closing in on Senator Clinton in superdelegates.
Obama and Clinton are in a tight race heading into the May 6 contest.
His big lead in North Carolina slips heading into May 6 primary; exodus of whites cited.