Our first 3e campaign - which went up to level 30 - became increasingly political the higher our level went. Our epic sessions usually consisted of one (albeit big and long) fight and the rest was talk.
By the time, my bladesinger was more or less the Toril-wide head of bladesingers, and, since the Queen was missing, nominally the acting ruler of all goodly elves on Toril. Of course, he didn't actually do the job, since he had more pressing matters - like saving the world, you know how it is in high-level campaigns - so he instead let the council of elders rule, but being able to introduce oneself as the acting leader of a whole race, with Evermeets resources at his disposal, helped in negotiations immensely. And of course he was a very capable combatant, which is always good in diplomacy (people want to listen to you, because the alternative - fighting - doesn't hold too much appeal)
The half-elf druid was, beyond being one of the most powerful of his kind, if not the most powerful, one of the leaders of the Verdant Lords, so he could call on the support of most nature churches and druid circles if he needed to.
The Wizard, finally, was the leader of his own mage guild, nominal ruler of a town (which was, if I remember correctly, a city by that time, since he put considerable resources and time into that city and guild).
Still, the three of us had many a hard time negotiating with this nation or that faction (who often had similar, or even more impressive power at their disposal) and it was great fun.
Of course, you need a decent DM for that sort of game (but luckily, ours was the best).
As I said, it can work well on high and epic levels, not just on lower ones.
