I don't see those as mutually exclusive. Also, term limits don't necessarily have to be one term. I was sorta thinking 8 years like the pres. or maybe 10 for an even decade. That would give freshmen time to learn the ropes, but not long enough to get too ensconced.
Parties are always going to support the incumbent as long as they will probably win, and in most congressional districts the votes are always solid along party lines. The incumbent doesn't have to be good, they just have to be not so beyond terrible as to make their constituents switch parties. There is no reason for the party to not support the incumbent otherwise.
I think you could also make the argument that after a few decades in congress, it becomes less and less likely that someone has a real sense of what life is like outside of that world, what the average citizen wants and needs from their government, and in some cases how the culture and technology of the world around them actually functions.
Even if a it means loosing a few good people, I think overall some reasonable term limits would have a positive impact overall. They don't even have to be short limits, even something like a 24 year limit would make a huge impact.
>>But if a pol is good at their job they shouldn't get pushed out; we just need to find ways so that they don't remain by inertia alone.
If you figure that one out...Let me know :-) We've had McConnell and Pelosi since the mid 80s! Inertia seems to be the main force in politics (why? I have no idea)
I think it has a lot to do with the two-party system. Many (most?) congressional districts are essentially locked to one party. Unless the incumbent did something egregious enough for their supporters to turn on them, why would their party not support them as their candidate? If they won by decent margin last time, they'll probably win again unless something major changed. Why make all the necessary investments to support a new candidate when it's cheaper and easier to support the incumbent? They would much rather put their money and time into the districts that might flip.