Since the first publication of Modern Constitutional Law forty years ago, it has continued to be one of the best sellers in a very competitive market. Over the years, many law professors have adopted this user-friendly casebook - which is no surprise, given the rave reviews the book has enjoyed. For example, Professor Thomas E. Baker stated that he has "been so loyal to the Rotunda brand name over the years," because it "remarkabl[y]" manages "to include all the important cases yet preserves a fuller set of opinions to guarantee 'thoughtful classroom discussion'." This Twelfth Edition incorporates many changes in Constitutional law, including limiting federal courts' power to review partisan state gerrymanders, limits on government-compelled speech, refusing to give the President immunity from subpoenas by prosecutors and Congress for the President's private papers, freeing churches from burdens on free exercise of religion, striking down abortion restrictions, and refining powers under the commerce clause.