Not saying the HST was a terrible thing, but they did not do a good job selling it. Most people felt like the Liberals attitude was 'nah nah, we're doing this and you can't stop us'. Conservatives of course play up any Liberal 'tax hike/remodeling' as a crime against humanity, which doesn't help with Joe-public. Average tax payer won't think about a joint effort when they hear HST, only the Liberals shoving it down their throats.
I wish McGuinty would have fought for Transit City more once Ford was elected, but he tucked tail and agreed to play nice. Oh well.