In politics, is the result what matters most?

FDR did a lot to help this country, but he was a pretty crooked politician from what I’ve heard. Winston Churchill wasn’t any better. Also, the Kennedys were pretty corrupt, let’s face it, with all Jack’s affairs and Joe’s rigged elections. But all these men did a lot of good for their country (depending on your opinion, but I think so), does their corruption really matter because the outcome was good? Is it alright to use lies to paint the truth?