Why was Umbridge hired if Snape also applied for the position? Surely Dumbledore would prefer Snape as the Defence against the Dark Arts teacher than a ministry official.
UPDATE: She was only hired because Dumbledore couldn't find anybody else. I can verify this with a quote from the Daily Prophet.
“This is not the first time in recent weeks that the Minister, Cornelius Fudge, has used new laws to effect improvements at the wizarding school. As recently as August 30th, Educational Decree Number Twenty-two was passed, to ensure that, in the event of the current Headmaster being unable to provide a candidate for a teaching post, the Ministry should select an appropriate person. ‘That’s how Dolores Umbridge came to be appointed to the teaching staff at Hogwarts,’ said Weasley last night. ‘Dumbledore couldn’t find anyone so the Minister put in Umbridge, and of course, she’s been an immediate success —'”