Read my lips: No new taxes

From dKosopedia

A campaign promise given to America by George H.W. Bush at the 1988 GOP convention. In 1990, it was clear the deficit was spiraling out of control so Bush had to prove himself the liar he was and broke the promise. It is widely believed to have cost Bush the election, and rightfully so, as he raised taxes on mostly the middle class, while leaving the rich mostly well off.