The crux of the matter is the hypocracy in both camps.
It was a big deal when Clinton & Gore smoked weed but for GWB being a recovered alcoholic and possibly using cocaine was "none of our business". The same pretty much happened for Al Gore and John Kerry with various parties raising a ruckus about their actual service while actual records of GWB's service are MIA (and we all know Cheney had different pans for his life).

I'm not trying to single out the Republicans in this, it happens on both sides (and all parties). I guess it's all in what you want to believe about a person to justify your positions.