The conventional wisdom on Justice Clarence Thomas is that he is an unimaginative intellectual featherweight and a clown.  The way in which his reputation was traduced in his confirmation hearings and his notorious lack of interest in participating in oral arguments are cited as evidence.  A new look at Justice Thomas's influence of the Court by Jeffrey Toobin  in the New Yorker sets this condescending notion on its head. 

From Walter Russell Mead's  New Blue Nightmare: Clarence Thomas and the Amendment of Doom

If Toobin's revisionist take is correct, (and I defer to his knowledge of the direction of modern constitutional thought) it means that liberal America has spent a generation mocking a Black man as an ignorant fool, even as constitutional scholars stand in growing amazement at the intellectual audacity, philosophical coherence and historical reflection embedded in his judicial work.

I recommend both Mead and the much longer Toobin article Partners: Will Clarence and Virginia Thomas succeed in killing Obama's health-care plan?     Don't let the New Yorker headline and a few snarky paragraphs deter you.  Toobin's article analyzes how Thomas's manner of approaching constitutional issues is changing the law and earning him more than just respect from legal thinkers across the political spectrum

According to Sanford Levinson, a left-leaning professor at the University of Texas School of Law, "Scalia is far more influential, because he has spent much of the last two decades campaigning around the nation for his views, but it would not surprise me if future historians find Thomas to be the more intellectually serious of the two."

Like many philosophers who think in terms of years and decades instead of days and weeks, Thomas has used his sharply reasoned dissents and concurring opinions over the years to influence his legal colleagues to think in ways that were not imaginable just a few years ago.

"Justices can be influential by indicating to lawyers the boundaries of what's possible," Eugene Volokh, a professor at U.C.L.A. School of Law and a widely read blogger, said. "There is conventional wisdom about what's possible, like 'Whatever you think about the Commerce Clause, no one is going to go back to the pre-1937 approach,' or 'The Second Amendment is a closed issue.' Thomas has shown that sometimes the conventional wisdom is wrong."