Sen. Orrin Hatch is a good example of why we should have term limits in Congress. If we had term limits, when he was getting toward the end of his limit, he and his political party would have been grooming a person to run in his place. And that person would have had to run on even terms with a challenger.
As it is, he is now 78 years old, has served 36 years as a senator and is seeking another six-year term. Yes, there are some people who live longer than 78 who maintain their energy and intellectual sharpness, but not many. And the odds of him living to the end of his seventh term are not that great.
So why would the Republican Party want him to be re-elected once more? Pretty simple really. As an incumbent, he already has a huge campaign war chest and a very high probability of being re-elected, in spite of his age. And if for some reason — like failing health — he is not able to finish his seventh term in office, the Republican Party will be able to appoint his replacement, who will then be able to serve without having to be elected, and will run as an incumbent for the next term, which will give him or her a great advantage in that election.