“Men desire to have some share in the management of public affairs chiefly on account of the importance which it gives them.”

Not always so...

True more often than not.

Congress and the Senate are perfect examples.

It is that very perception that makes government act as though they are superior to the Constitutional sovereigns.

I actually can't think of any other reason than self-importance to seek public office, except ancillary ones such as the modest pay and a few perqs, or fringe benefits. If it turns out well, however, it can provide ample after effects of high paying speaking engagements and book sales.