BARTLETT, Ill. — The Republican Party is on the ropes in America’s upscale suburbs, usually friendly territory that is poised to rebuke President Trump and deliver the House majority to the Democrats, in the final days of a volatile fall campaign.

In suburban Chicago, Rep. Peter Roskam is battling to survive amid political headwinds Republicans last experienced in the late 2000s with dual blue waves that booted the GOP from power in Congress and elevated Illinois Democrat Barack Obama to the White House. Roskam always beat the odds, overcoming challenges more daunting than his Democratic opponent this year, businessman Sean Casten.