How come the President's approval ratings don't necessarily reflect on the VP?

[pragmatic liberal]

Incumbent VPs have a few handicaps.

After one party has held the WH for eight years, and especially when there is no incumbent president running, the pendulum effect kicks in and there's a sense among the electorate that it's "time for a change." The Vice President is someone who was first introduced to the national electorate eight years before and can seem like a bit of a stale figure.

Still, the "time for a change" factor can in theory be overcome, especially if the outgoing president is popular, but the vice president is often poorly placed to take advantage of the administration's achievements for a couple of reasons. Dick Cheney notwithstanding, even "influential" vice presidents like Gore are hardly the most public or influential of presidential advisers and what influence they do exert often comes behind the scenes. Thus vice presidents suffer in public perceptions both because they don't get enough credit for the administration's achievements and because by taking on lower-level initiatives within the WH, they don't develop a strong, independent public identity.

So in the end, vice presidents wind up being too well-known to take advantage of the desire for a "fresh face" yet too anonymous to claim much credit for the incumbent administration's achievements. As a result, even when the incumbent is popular, incumbent vice presidents are at a narrow disadvantage.

For this reason, I sometimes wonder if the parties are better off NOT running the vice president when the president retires.