The problem is eminently practical. People always say they want young politicians, “in tune” with the working population; that means the average age for politicians has declined overall. Barack Obama will leave office at 55, which means he will likely enjoy something between 20 and 40 years of pension, at least 10 of those at a time when most of the population is still supposed to work. Blair and Clinton both left office at 54, in perfect physical health. Because private-sector salaries have skyrocketed since the '80s, their “peers” at that point are raking in several $millions per year – it’s entirely natural for them to try and get the same deal, especially after being forced to live 20 years under continuous public scrutiny. And there are hundreds of senators, congressmen and MPs who are much, much younger and will leave much earlier than that - Nick Clegg is 49 and has already done it all.
Lowering the average age of politicians while increasing inequality in the private sector, coupled with righteous anger at politicians’ salaries, resulted in a system where high office is just a very long audition to join the global elite. Counter-intuitively, the best solution might actually be to reverse the trend: raise age barriers to high office, so that people who get there will have nothing to lose. Trying to “police away” the problem will not work: these people have armies of lawyers and accountants, hell they are lawyers and they write those laws in the first place, so they know all the loopholes.