Less than one third of American voters now approve of the way President Bush is handling his job. The way I see it, this is one of the weaknesses of the American Presidential system. A President can become so unpopular that he becomes what Americans refer to as a lame duck president. His Presidency may have failed in the eyes of the electorate but he still has time in his term so no one can really do anything about the situation.
In a parliamentary system if a Prime Minister becomes hideously unpopular either the government will fall and an early election will be held, or if the governing party is strong enough they can just vote for a new leader, and therefore a new prime minister, giving themselves a fresh start without having to sit around for 2 more years and hope things don't get worse. The Republican party must be praying that the next 2 years pass quickly and they don't loose too many seats in the mid term elections.