This OECD chart (bottom of the page) published by Heritage says it all
The U.S. rate is well above the 25 percent average of other developed nations in the Organization for Economic Cooperation and Development (OECD). In fact, the U.S. rate is almost 15 percentage points higher than the OECD average.
This gaping disparity means every other country that we compete with for new investment is better situated to land that new investment and the jobs that come with it, because the after-tax return from that investment promises to be higher in those lower-taxed nations.
Our high rate also makes our businesses prime targets for takeovers by businesses headquartered in foreign countries, because their worldwide profits are no longer subject to the highest-in-the-world U.S. corporate tax rate. Until Congress cuts the rate, more and more iconic U.S. businesses such as Anheuser-Busch (which was bought by its Belgian competitor InBev in 2008) will be bought by their foreign competitors.
To get back in line with international norms, Congress needs to reduce the rate so the combined federal and state rate matches or falls below the OECD average. Some will contend that with deficits north of $1 trillion annually, we simply can't afford such a large rate reduction. But the actions of the nations we compete with for new investment show that these nations understand that lowering the corporate tax rate is necessary because of the boost to economic growth it provides.
Only recently have GOP candidates been pushing a corporate tax cut that would make us more competitive. Mitt Romney has made it the centerpiece of his plan to revitalize the economy. Of course, the Democrats resist the idea, unless there are corresponding tax increases on the "rich," although they don't object to the concept of a corporate tax rate cut.
It's a dubious honor to be sure, and one that must be rectified before we can experience the kind of strong growth that will pull us out of the hole we're in.