President Bush's list of domestic accomplishments is already pretty thin. No Child Left Behind is now universally despised among conservative activists. Medicare Part D epitomized Bush's big spending ways and arguably paved the way for Obamacare. And even Bush's tax cuts are looking to be pretty temporary in nature.

The one saving grace Bush still has on the domestic front is the Supreme Court. Chief Justice John Roberts and Justice Sam Alito have so far proved to be good reliable conservative votes. But all that may change after Obamacare hits the Supreme Court.

Almost everybody assumes that Justices Clarence Thomas, Antonin Scalia, and Sam Alito will side with the National Federation of Independent Businesses and find Obamacare's individual mandate unconstitutional. Justice Anthony Kennedy is the consummate swing vote. But what about Roberts? The New Republic's Jonathan Cohn flags an American Bar Association survey finding that many scholars believe Roberts, not Kennedy, is the most likely conservative to join the Court's liberals in upholding Obamacare.

This is not as crazy as it first sounds. Kennedy has voted to limit Congress' Commerce Clause power twice: once in U.S. v Lopez, and again in U.S. v Morrison. He also wrote a separate concurrence stressing the limited nature of his agreement with the government in U.S. v Comstock. “This is a discrete and narrow exercise of authority over a small class of persons already subject to the federal power,” Kennedy said in defense of Congress’ power to further detain inmates already in federal prisons. Roberts simply signed on to liberal Justice Stephen Breyer's majority opinion.

If Roberts does end up being the fifth and deciding vote to uphold Obamacare, Bush's Supreme Court legacy will be regarded as a failure too. His reputation among conservatives will never recover.