Democrats are hoping Hispanic voters will help them win control of Congress in midterm elections next month, and are promising help for immigrants in return. Turnout is historically low for this swelling segment of the US electorate, but the community showed its political potential with massive demonstrations on immigration reform earlier this year -- and the Republican-controlled Congress has delivered little joy on their top issue. "The key is getting Hispanic voters out to vote," Democratic Party president Howard Dean said ahead of November 7 elections in which all 435 seats in the House of Representatives and a third of 100 Senate seats are up for grabs.