[cnn-photo-caption image= http://i.cdn.turner.com/cnn/2008/images/05/27/art.bushmccain.gi.jpg caption="Will Bush help or hurt McCain?"](CNN) - Is President Bush an asset or liability to John McCain's presidential bid?
That's the question being asked Tuesday as the president prepares to make his first campaign appearance with the presumptive Republican nominee later Tuesday at a private fundraiser in Phoenix.
A look at CNN's most recent poll numbers on Bush's approval ratings shows the president's appearance could be a mixed blessing for the Arizona senator.
Among the American public as a whole, Bush's approval rating has never been lower, and his disapproval rating is the highest of any president in modern history. In a CNN/Opinion Research Corporation poll conducted last month, only 28 percent of Americans said they approved of the president's job performance, while 71 percent said they disapproved.
But the president still remains relatively popular among Republican voters (and, presumably, the party's biggest fundraisers), the CNN/Opinion Research Corporation poll also showed - nearly two-thirds gave him a positive rating.