Term Limits are absolutely necessary in a Republic. As Madison notes, some legislators will become masters. In today’s world this comes from tenure and all the named and unnamed privileges afforded to long-standing legislators. This gives undue influence of citizens represented by tenured legislators (masters) over citizens represented by freshman or less tenured legislators. A Republic must protect the less represented citizen from citizens that continually elect the same legislators to gain undue power, privilege and influence in the legislative branch. The only way is to limit the term an individual can serve in the US Congress.
Then perhaps you can make a citation to what he actually said with sources and in context, please. Madison (in Federalist 50-52) pointed out that the checks and balances within a limited government precluded such despotism. Madison also preferred to leave the decision as to when to remove a legislator up to the people, as I cited in his own words above.
The rest of your post is equally unsupported assertion.