Legal scholars expressed little surprise Thursday that the conservative chief justice of the United States -- John G. Roberts Jr. -- proved to be the key vote in upholding the constitutionality of the Affordable Care Act . Breaking down the court 's decision . `` Had the court ruled as the four dissenters would have had it -- in a 5-4 decision , red versus blue -- that the signature act of a Democratic administration was unconstitutional , I think that would have been a very serious threat to the legitimacy of the court , '' said Timothy S. Jost , a professor at Washington and Lee University School of Law in Lexington , Virginia . What the health care ruling means to you . `` I think Americans are already very skeptical about the rule of law in the United States and believe that the court is essentially a third political branch , '' he said in a telephone interview . The 57-year-old Roberts may have been thinking about the court 's perceived legitimacy and about his own legacy when he crafted the decision , which could n't have been an easy one , Jost said . `` I think he probably had to think very long and hard about how to rule in this case , '' the professor said . No matter what it does , high court is seen as political . In 2005 , when then-President George W. Bush tapped Roberts to be the 17th chief justice of the United States , then-Sen. Barack Obama voted against his confirmation . During his confirmation hearing , Roberts said he saw his role as a potential justice to make rulings based on the Constitution and not to set policy -- or , as he described it , `` to call balls and strikes , not pitch or bat . '' `` I come before this committee with no agenda , no platform , '' he told the Senate Judiciary Committee at the time . `` I will approach every case with an open mind . '' Since then , Roberts ' stances on campaign finance and affirmative action had led some observers to brand him a judicial activist . Obama : Supreme Court ruling on health care a victory for all Americans . But Neal Katyal , a professor of law at Georgetown University in Washington , said that Roberts , `` more than almost any justice on the court today , appreciates the institutional role of the Supreme Court and American democracy . He 's a student of history , and I think today 's decision was a really resounding reflection of the chief justice 's values , which are ( that ) law is not just politics and the Constitution is not just politics , and we should think about decisions impartially and dispassionately and come to the right ones . '' Katyal , who served in the Justice Department under the Clinton administration , called Thursday 's decision `` a resounding victory for the rule of law in America . '' Ruling plays into campaign narrative for both sides . `` I was n't that surprised '' by the decision , said Randy E. Barnett , a law professor at Georgetown who helped write the brief for the National Federation of Business that challenged the law . `` I said from day one that the Supreme Court always bends over backwards to uphold laws of Congress . That 's the reason why our fight was always an uphill fight . '' The law 's ultimate fate , he predicted , will be decided not in any court but at the ballot box in November . `` The people will decide whether they approve of this tax , this so-called tax that has been imposed upon them , '' he said in a telephone interview . And the election may also be about appointing justices who do not bend over backward to uphold the laws of Congress , he said , `` because the Congress can not be the judge of the scope of its own powers , and we need an independent judiciary to do that . '' Regardless of what happens this fall , presidential historian Douglas Brinkley said that Roberts himself made a difference with his ruling Thursday -- not only affecting how some view the court , but how they see the chief justice himself . The historian compared Roberts to former Chief Justice Charles Evan Hughes , a former Republican governor and presidential candidate who nonetheless sided with liberal justices -- and Democratic President Franklin Delano Roosevelt -- in finding Social Security to be constitutional . `` Supreme Court Chief Justice Roberts has etched himself in history now , '' Brinkley told CNN . `` This , today , showed that Roberts had ... deep thought . He really played the constitutional lawyer and justice here , and I think his stock goes very high . '' How the justices voted , what they wrote . Opinion : Are voters ready to move on ?
`` Roberts has etched himself in history , '' a historian says . A professor says that a vote against Obamacare would 've threatened the court 's legitimacy . The court `` always bends over backwards '' to uphold Congress ' laws , another professor says . In his confirmation hearing , Roberts vowed he 'd be open-minded and had `` no agenda ''