DENVER – Democrats are trying to motivate college students and others inclined to sit out this fall’s elections to help decide some of the closest congressional races in the nation.

Democratic National Committee chairwoman Debbie Wasserman Schultz helped kick off what the party is calling its voter-expansion campaign with a voter-registration drive at Metropolitan State University in Denver. It will include more drives at colleges around the state as well as home visits to people deemed likely to vote Democratic but who aren’t registered.

Wasserman Schultz said that approach could be particularly helpful in the suburban Denver race between U.S. Rep. Mike Coffman and Democratic challenger Andrew Romanoff, one of the most closely watched House contests in the country.

Turnout is key because the president’s party usually loses seats in Congress in off-year elections and typically fewer than half of people eligible to vote cast ballots in those races. The party plans to hire a leader for the Colorado outreach effort and is recruiting thousands of poll watchers to work in Colorado and other competitive states to make sure votes that are cast are counted.

Democrat Sen. Mark Udall is also in a tight race against U.S. Rep. Cory Gardner as Republicans try to pick up six Senate seats to win control of the chamber.

Republicans and conservative groups have also been trying to court younger voters in the state by blaming Udall for the nation’s debt. The Koch-backed group Generation Opportunity has been running an ad featuring an older man in a suit sitting in a shopping cart as he pulls items from the shelves asking for a young woman to pick up the tab.