He has never wanted to write 12-tone music. Back in his student days he was forced to, but tried to do it in his own way. He remembers bringing in a 12-tone work to his teacher, the Italian avant-gardist Luciano Berio, at Mills College.
"My solution was simple," Reich said. Instead of putting the 12-tone row through its de rigueur permutations, he simply repeated it, over and over.
"So, Berio saw this and he said 'You know, if you want to write tonal music why don't you write tonal music?' And I said, 'That's what I'm trying to do.'"
Steve Reich's New Deal
(as Tim Mangan alerts us, even if Reich seems to have a penchant for corduroy and khakis, composers nowadays wear denim -- a GAP ad can't be that far in the future).