Now that corporations are people, there is absolutely no need whatsoever for two rate structures, one for corporations and and one for natural people.  Corporations should not be awarded more favorable tax rates than the average Joe.

Also, Reagan started with a top rate of 70% - plenty of meat on the bone for rate reduction.  Now that the top rate is less than 40%, rate reduction will only result in reduced government revenue, with no discernible impact on the economy.  See Kansas for the results of reducing already low tax rates.