His one innovation was that he was the first to try the "I'm different than those other democrats," scam. Clinton borrowed his technique of repackaging liberalism by wrapping it in moderate rhetoric and calling it NEW AND IMPROVED. Clinton succeded for a while.
The problem for Gary is that the public has now seen the scam over and over and it turns out to be the same old baloney. In fact, the 2002 election might be properly regarded as a repudiation of democrats who run to the center and govern to the left. Noone really believes them anymore. Noone will believe Hart.