Democrats decline: Good news for Romney?

An analysis out today from Bloomberg suggests that the number of self-identified Democrats in key swing states is on the decline. Meanwhile, independents are on the rise:

The collective total of independents grew by about 443,000 in Colorado, Florida, Iowa, Nevada, New Hampshire and North Carolina since the 2008 election, according to data compiled by Bloomberg from state election officials.

During the same time, Democrats saw a net decline of about 480,000 in those six states, while Republicans -- boosted in part by a competitive primary earlier this year -- added roughly 38,000 voters in them, the analysis shows.

“Democrats hit the high-water mark for registration in 2008, so it’s natural that they are going to see some drop off,” said Michelle Diggles, a senior policy analyst with the Democratic-leaning Third Way research group in Washington who conducted a similar study earlier this year.

The rise of independent voters has had a major impact on recent election results.

In 2008, President Barack Obama won 52 percent of the independent vote, according to national exit polls, which was one percentage less than his overall total. Senator John McCain of Arizona, his Republican opponent, collected 44 percent of the independent vote -- 2 points less than his overall total. Independents represented 29 percent of the total electorate that year.

The independent vote is always a key factor in deciding elections.  But will the exodus from the Democratic Party translate into a more conservative swing in votes?