Ethics vs. morals?

Here's a question I've wondered about for some time, and haven't really found a satisfactory answer to: What exactly is the difference between "ethics" and "morals"? As in " this politician demonstrates good ethical and moral principles in his decision-making" It seems to me that these two terms are often used in conjunction with each other, but no one seems to make a distinction between them. Is it possible to be immoral but still act ethically? How 'bout the other way around?