Early voting in the November elections begins this week, and U.S. Democratic Representative Betsy Markey’s battle to hold her 4th Congressional District seat in northern Colorado is perhaps among the most difficult in the country. Republican Cory Gardner is a strong opponent, notes KUNC radio, but Markey is holding her own.

Potential voters are likely reeling from the onslaught of advertising, including a new one from the National Republican Congressional Committee admonishing Markey for often voting House Speaker Nancy Pelosi’s Democratic Party line (via the Fort Collins Coloradoan). Nevertheless, the latest ad from Markey’s campaign defends her voting record, while criticizing Gardner as a career politician. Big money pouring into the race guarantees more ads to come.

Despite many pundits writing Markey off as a casualty of an expected GOP avalanche, and despite the Democratic Congressional Campaign Committee making cutbacks on spending in the race, she was still able to bring in some $858,000 in the third quarter, placing her at $3.1 million raised this year, according to CW2. “We are gaining momentum and excitement, but we’ve never taken anything for granted,” Markey says in a press release.

Meanwhile, Gardner has received the endorsement of the pro-life Susan B. Anthony List.