While Mitt Romney and President Barack Obama debate who's is going to help the middle class more, the two candidates are sidestepping one of the most pressing financial issues facing Americans: paying for basic shelter and transportation costs.In the 25 largest cities in America, middle-class households are shelling out 59 percent of their paychecks for these two basic necessities, according to the report released on Thursday from the Center on Housing Policy, a nonprofit housing policy organization.