Does the End Justify the Means?

I read an article about a priest who ran for political office, in another country, to eliminate political corruption. This is forbidden for priests, but he did it anyway. So he believes it's OK to break the rules if he has good intentions. This way of thinking is common in that country. But it leads to the same corruption he wants to eliminate. What if someone offers him a bribe, & tells him to think of the poor he can help with this money? A priest is not immune from temptation. So what will stop him from justifying acceptance of the bribe, if he believes that something "good" can come out of it? Wouldn't this be the same kind of rationalization he used to run for office in the first place? And if he's willing to break any rule he wants, what kind of message is he sending to others? Is he behaving differently from corrupt politicians, who also break any rule they want? While I can understand his frustration, I think it would be more beneficial if he rejects the idea that the end justifies the means, and sets a good example. How? By doing his duty as a priest, & living the virtues, such as obedience. Maybe then, others may emulate him & obey the law, rather than come up with justifications to break it.