Absent a Battle Cry, War for the House Is Fought at Home
Battle for control of House is being fought old fashioned way: candidate by candidate and district by district and could depend less on political themes than on chain of local circumstances; in year marked by pro-incumbent contentment with economy, only 65 races are even considered by Republicans and Democrats to be truly competitive; yet, with Republicans holding one of slimmest majorities of century, Democrats need net gain of just 11 seats to reclaim control; 10 pivotal House races listed; some incumbents comment; photos (M)