A president spends his 4th year campaigning to retain his position. If a federal employee of a non political status wishes to run for office, he / she must take Federal leave from their position in order to devote time to run a campaign. Running a campaign takes the president away from the critical 24/ 7 job. In today’s world this just doesn't make since. Currently, the President, no matter who he/ she is, may run their campaign on the job.
A six year limit for all congress members of the house and senate would give the opportunity for new individuals with fresh ideas to hold congressional seats and implement ideas for this ever changing country.