Since Bush was inaugurated in 2001, the country slowly learned as deficits blossomed that Republicans were Bad on fiscal issues. So in the 2008 Presidential race, a big majority of voters went with the Democrats in the hopes that they would be Good. But the past six months have proved that they are, in fact, simply Worse. As a result, Democrat poll numbers are slipping.
That may be good for Republicans, who might be viewed as a the less-bad party. It isn't particularly good for the country.