Yup, approval rating for H.W. Bush was around 40's-50's prior to reelection in 1992 but he lost, however Bill Clinton had 40's-50's approval rating prior to reelection in 1996 but he won, also G.W. Bush had too but won in 2004 reelection.
Situation could be different so we don't know about who will win in next year.
Ron Paul.