Let me just say, in my personal opinion, that is a load of crap! The corporate tax rate is in fact unfairly high, but the number of loopholes in the tax system cut the actual tax rate in half, making taxes paid more than reasonable.
Offshoring jobs is all about the increased profit from using low cost labor. Large Corporations will do whatever they can and whatever it takes to make that extra penny, regardless of who they have to step on to do it!
As I said in a comment earlier, I worked as an engineer and manager for a large corporation that forced us to lay off a bunch of employees while we were trying to hire to meet contractual requirements. We told them we couldn't lay anyone off. That we needed MORE employees. They forced us to lay people off anyway and their reasoning was that they want the stock value bounce (that always occurs after a layoff) for their quarterly reports...
We need to fix the tax system. There's no argument there. But, don't be fooled by tax brackets that no one pays or let the media convince you that the large corporations are being abused! Here's just one of MANY articles and reports you can easily find that talk about the "real" tax rates that are being paid.