Washington ? President Bush’s job-approval rating fell to an all-time low – 34 percent – in a poll published Tuesday. That puts him not far above Richard Nixon’s Watergate-era nadir and raises questions about how effectively he can govern in his remaining years in office.

The poll, conducted nationwide by CBS News between last Wednesday and Saturday, found that 59 percent of U.S. adults disapproved of Bush’s job performance. His 34 percent approval rating was the lowest since he took office in 2001, eight points lower than in January. The poll’s margin of error was plus or minus 3 percentage points.

A politically toxic mix of messes has dragged Bush down, including his handling of Hurricane Katrina, the ill-fated Harriet Miers’ Supreme Court nomination, the upsurge of violence in Iraq, and the deal to allow a state-owned Arab company to manage terminals at six U.S. ports.

Bush’s approval rating is far below those registered by three of the last four two-term presidents in February of their sixth year: Dwight Eisenhower (64 percent), Ronald Reagan (63.50 percent) and Bill Clinton (57 percent). Only Nixon, at 27.5 percent in February 1974 – six months before he resigned – was less popular than Bush is now.

Bush’s slide is prompting many GOP lawmakers to abandon him as they face tough elections in November and don’t want to carry his political baggage into battle.

“He hasn’t been in a position for some time to press successfully most of the controversial issues on which the country is divided, and there’s substantial opposition in Washington,” said Thomas E. Mann, a senior fellow at the Brookings Institution, a center-left Washington think tank. “We saw that on Social Security reform. We’re likely to see it on immigration reform.”

Bush was asked about the poll in an interview Tuesday with ABC News. His answer:

“If I worried about polls, I would be – I wouldn’t be doing my job. And, look, I fully understand that when you do hard things, it creates consternation at times. And, you know, I’ve been up in the polls, and I’ve been down in the polls.”