Further to this ; in Canada, we have to constantly, and directly, worry about the US corporate tax rate. If it drops too low, compared to our tax rate? Companies can VERY easily flee to the US, and with the FTA/NAFTA/whatever it's called now?

No issues with product across the border.

So even though many Canadians are in favour of a higher corporate tax rate, it would literally be deadly. We must compete, we must race to the bottom, else corporations will move South.