Congressional Republicans are enjoying their closest margin with Democrats on a generic ballot in years, according to a new poll. 

50 percent of registered voters say they prefer a generic Democratic candidate versus a 44 percent who said they'd vote for a generic Republican candidate in a CNN/Opinion Research poll released Tuesday.

While still trailing, the six-point margin among registered voters is the tightest it's been since 2004, according to past CNN polls, though the shift is within the poll's margin of error.

That year, Democrats maintained a 49-45 edge over Republicans, which expanded to a 20-point gap in the 2006 midterm elections which swept Democrats into power.

The generic matchup among registered voters is an improvement over a year ago, as well, when 53 percent said they supported Democrats over 45 percent for Republicans.

More broadly, Democrats maintain a 10 point edge over Republicans going into the 2010 midterm elections among all poll respondents.

The poll, conducted October 30-November 1, has a three percent margin of error.