Image caption Independents who once supported Mr Obama are now turning on him

Two polls released on Thursday suggest that America's independent voters are continuing to sour on the Democrats.

Independent voters propelled President Obama's party to victories in 2006 and 2008, but a majority of them now hold negative views of Democratic policies.

An Associated Press-GfK poll found only one third of independent voters want Democrats to control congress.

A Pew Research Center poll suggests Republicans have a 13 point advantage among independents.

In 2006, when Democrats took control of congress, Democrats had an 18 point lead with independents.

Pew also found that independents are now the largest group of voters. Their numbers have swelled in recent years as disenchantment with both major parties has grown.

Likely voters

Voter turnout is seen as a critical factor in November's elections. Mid-terms traditionally have much lower turnout than presidential year elections, and the party with the most energized base usually benefits.

The Pew poll found Republicans significantly more likely to vote than Democrats, while independents are more likely to vote in this election than any in Pew's data set, which dates back to 1994.

In the AP-GfK poll, only around 30% of independents think the country is headed in the right direction and more than half disapprove of President Barack Obama's performance.