That's what the economic data suggest, at least the data through 2012. After reproducing what Matthew Yglesias calls the most important chart about the American economy you'll see this year, Yglesias explains:
For a long time, most of the gains from economic growth went to the bottom 90 percent of the income distribution. And, after all, the bottom 90 percent includes the vast majority of people. Since 1980, that hasn't been the case. And for the first several years of the current expansion, the bottom 90 percent saw inflation-adjusted incomes continues to fall.
The chart was produced by economist Pavlina Tcherneva.