Hillary Rodham Clinton, under pressure from the left wing of her Democratic Party to aggressively campaign against income inequality, voiced concern about the hefty paychecks of some corporate executives in an email to supporters.

Striking a populist note, Clinton, who announced on Sunday she was running for president in 2016, said American families were still facing financial hardship at a time "when the average CEO makes about 300 times what the average worker makes."

In a tightly scripted campaign launch in which there were few surprises, the comments were unexpected, at least by progressives, who saw them as an early sign she may shift away from the centrist economic policies pursued by her husband, former President Bill Clinton.