WASHINGTON (Reuters) -President George W. Bush”s job approval rating has fallen to a new low of 39 percent in an NBC News/Wall Street Journal poll released on Wednesday.

Bush”s approval rating dipped in the poll below a mid-September ranking of 40 percent. The survey also found only 28 percent of respondents believed the country was headed in the right direction, NBC reported.

Bush”s political challenges have been piling up in recent weeks, from criticism over his handling of Hurricane Katrina, to growing unease over rising gas prices to conservative discord over the nomination of Harriet Miers to the U.S. Supreme Court.

Many conservatives are outraged that Bush picked the White House insider with no judicial experience instead of a judge with clear-cut conservative credentials who could be counted on to move the high court firmly to the right.

Twenty-nine percent of people surveyed said Miers was qualified to serve on the highest court in the United States, while 24 percent thought she was not qualified and 46 percent said they did not know enough about her, NBC said.

The poll also found that strong majorities did not believe that recent charges against former House Republican leader Tom DeLay of Texas or a federal investigation of Senate Majority Leader Bill Frist, a Tennessee Republican, were politically motivated, NBC said.

DeLay has been indicted in Texas on money-laundering and conspiracy charges linked to campaign financing. Frist is being investigated over a stock sale.

With the 2006 congressional elections a year away, 48 percent of respondents said they preferred a Democratic-controlled Congress, compared with 39 percent who said they preferred Republican leadership, NBC said.

The 9-point difference was the largest margin between the parties in the 11 years the NBC News/Wall Street Journal poll had been tracking the question, NBC said.

The poll of 807 adults was conducted from Saturday to Monday and had a margin of error of plus or minus 3.4 percentage points.