Big gains in 2006 and 2008 produced the Democrats' current 258-177 majority in the U.S. House. That gives the Democrats a 41-seat cushion against a reversal in fortune. But the party holding the White House typically loses seats in a midterm election year, and the recession -- and a conservative backlash to policies pursued by President Obama -- could make 2010 tougher than usual for the party in power.