The top 1% already pays over 70% of the country's tax bill; I'd say that they are already paying far more than their fair share. Also, it isn't really as simple as finding loopholes and closing them. There really isn't such a thing as a corporate tax, for example. Companies just pass those tax hikes on to the consumer, driving prices up. So we can't just say shut the loopholes and jack up their taxes. Which is a good thing. Increasing taxes rarely leads to any significant gains in government income anyway.