“We’re coming, and we’re going to getcha,” the usually mild-mannered Gov. Tom Vilsack of Iowa told the gathering Saturday. Did Disney World make these Democrats a bit, well, goofy? Hardly. They have plenty of reasons to feel optimistic about next year’s elections. Bush’s poll numbers remain at politically perilous levels, although they have begun to inch up. The public also is still dissatisfied with how the Bush administration has handled the Iraq war, the economy, and Hurricane Katrina. In addition, ethics scandals have ensnared Republicans: A Texas prosecutor has indicted Rep. Tom DeLay, R-Texas, on political money-laundering charges, forcing DeLay...