Simplify the following text for a Grade 14 native English-speaking person.
Original: When contemporary David Cameron was elected leader of the Conservative Party in 2005 , Johnson was re-appointed to the front bench as Shadow Minister for Higher Education and resigned as editor of The Spectator to concentrate on his new role .
Simplified: When David Cameron was elected leader of the Conservative Party in 2005 , Johnson was re-appointed to the front bench as Shadow Minister for Higher Education and resigned as editor of The Spectator .