. . . What terms limits have actually done:
- They have made the parties MUCH more powerful: Unless you are either independently wealthy or retired, you need a job once your time in the legislature is done. As a practical matter, the likely source of that job is likely to be your party but if you want that post-legislature job, you better toe the party line while you are in.
- They have made the bureaucrats MUCH more powerful: Prior to term limits a good Representative or Senator could make a bad bureaucrat's life very difficult. Now, they really can't. By the time they have been around long enough to know that Bureaucrat X isn't doing his/her job, the legislator is on their way out the door and can't do anything about it.
- They have made the Lobbyists MUCH more powerful: Prior to term limits lobbyists asked legislators for things that they wanted. Now they basically dictate because the legislators don't know what the heck is going on. Additionally, if your post-legislature job is NOT provided by your party (see #1) then it will most likely be provided by a lobbyist but you aren't getting that job unless you did that lobbyist's bidding when you were in the legislature.
- They have given legislators an even shorter view of the world. This was a problem before term limits and it is an inherent problem of any representative democracy because it encourages the elected officials to have an outlook that basically only runs to the next election. Before term limits at least SOME legislators realized or presumed that they would be around for longer than two or four years so they didn't want to do anything that would put the State in a difficult situation 10 or 20 years down the road because they thought there was a decent chance that they might have to fix that problem in 10 or 20 years. Now they have no such concern. They absolutely KNOW that they cannot maintain their current office for 10 or 20 years so kicking difficult issues down the road for some other people to deal with later which was always an attractive option for officials facing reelection is an even more attractive option.
Bottom line, support term limits if you want a substantial portion of your legislators to be retired or independently wealthy and if you want to increase the power of Political Parties, Bureaucrats, and Lobbyists at the expense of the voters along with increasing the chance that the elected officials fail to plan for anything beyond a very short timeframe.
If you would rather have legislators from different walks of life and you prefer the voters have power rather than the Political Parties, Bureaucrats, and Lobbyists along with getting at least some long-term thinking from your elected officials then you should oppose term limits.
I agree with some of this, and disagree with just as much.
1. There is an argument that--at least at the national level--the weakened parties are either a part of the problem or a symptom of it. Weakening the parties began during the Progressive Era, and it was done by design, as progressives ID'd parties as the main source of corruption in politics. They may have been corrupt, like pretty much everything else in politics is, but they also exercised party discipline because they knew the voters could and would hold them responsible. For example, when GOP passed the "McKinley Tariff" of 1890, it seemed to be the major cause of growing economic hardships facing farmers. It wasn't just William McKinley who suffered, the GOP got wiped out in the mid-term elections later that year, and President Benjamin Harrison was defeated for re-election in 1892. Grover Cleveland was handily elected to a second (and non-consecutive) term as President that year. Nowadays, many of the national political stars operate as lone wolves, unrestrained by party discipline, and it's harder to pin the tail on who's responsible for the latest fiasco.
3. Seems like more-powerful parties would fix much of the problem that you identify here.
4. The other side of the argument here is that the pols will be less concerned about their own re-elections, and so will be more likely to do the more responsible thing. Taking the difficult steps to fix problems that have built up over generations of bad government is politically dangerous. People whose idea of a career is a lifetime in politics can't be any more willing to take such steps than people who know they are only going to be around a relatively short time.
To your last comment, I don't think lifetime office-holding brings us the diversity of professions, viewpoints and opinions that you are advocating. Most office-holders now (at the national level, where there no term-limits) are lawyers. I can't see that terms limits would make that worse.