John McCain is making the case that he should be elected president as a check on a Democratic Congress that he says is determined to increase taxes and the size of government.

McCain says, "That's what's going to happen if the Democrats have total control of Washington." And he says "We can't let that happen."

Campaigning in Iowa, the Arizona senator is promising to "take America in a new direction" from his first day in office.

Barack Obama is leading in the polls and Democrats, who currently control the House and Senate, are on track for sizable gains in both houses.

McCain is dismissing the poll numbers, and tells NBC's "Meet the Press" his campaign is "doing fine." He admits it's going to be a very close race, but he says he believes he's going to win it.