If Romney loses, Ryan will be seen as a leading White House contender in 2016. He will be a national party figure even without being a top member of the House leadership. That could breed resentment among current Republican leaders and perhaps splinter coalitions within the already fractured GOP alliances at the top of the House.
A return also would make Ryan a leading target for Democrats. For the next few years, Democrats would lay traps in legislation, forcing him to take sides on measures that could come back to haunt him during a presidential bid.
That is why some of Ryan's biggest boosters are considering whether it wouldn't be better for Ryan to resign from the House. He could write a book "saving America" is a theme often bandied about or teach at a university.
VP Ryan? Prof. Ryan? GOP nominee's future unclear