[jfengel]

All other things being equal it is in their best interest to re-elect the incumbent. Seniority and connections figure into what posts you get and what influence you have. McConnell's and Feinstein's constituents have an outsized influence on the proceedings. Why would Kentuckians cede control of the Senate in favor of a politician, no matter how skilled, who had zero seniority?

I'm not especially in favor of short term limits, since there is a benefit to politicians with experience. But I'd definitely consider options that better balance their reasonable desire to elect experienced and influential candidates with the very heavy hand that experience puts on everybody else.

[bombcar]

Once you realize people vote for parties not persons it all makes sense.

Heck, California has gone so far as to have all their senate elections be between two members of the same party.

[jfengel]

And voting for the party is sensible. Most important votes happen along party lines. Including the most important, for Speaker and Majority Leader, who set the agenda.

Most other votes will be largely sublimated to the party priorities. The individuals will determine the specific contents of what they're voting on, but in general the person from the other party is going to vote against the things you're most interested in. You may watch your party vote on things that aren't your favorite, but it's unlikely they'll be repugnant to you. That's how they got to be your allies.

If you want to get more involved than that, you show up for the primaries. That's a multi-way contest to find the person who best represents you and your allies. That's where the party priorities get set. People who vote only in the general election are missing out on the real work of politics.