The Senate is the least-democratic representative institution in the world. The proof of it is, the Supreme Court struck down certain states' attempts to institute a similar system in their state legislators (e.g., two state senators from each county) as a violation of the one-person, one-vote principle.
According to the last census, the population of Alaska is 710,231. By comparison, the population of say, Texas, was 25,145,561. That means TX has 35 times more people than Alaska, yet they both have the same representation in the Senate: two.
Another way to put it: a voter in Alaska has THIRTY-FIVE TIMES the voting power of a Texas voter. This is a rank injustice.
Therefore, I propose making the Senate partially proportionate to the population. I say "partially" because we don't want to throw the whole thing away. Certainly there's value in Jefferson's "cooling saucer" concept. Therefore, my proposal is only this:
The one-third largest states get one more senator (three total); one-third smallest states get one less senator (one total); the remaining states in the middle (one-third plus any remainder) get the same two senators as currently set forth. That system would still ensure we'd keep the same "three-class" system stipulated by the Constitution. Oh, one more change: I'd add DC to the list of represented states.
Thus, the relevant section of Article I should now read:
"Section. 3. The Senate of the United States shall be composed of Senators from each State and District of Columbia, elected by the people thereof for six Years; and each Senator shall have one Vote. The electors in each State shall have the qualifications requisite for electors of the most numerous branch of the State legislatures.[...]
"Senators shall be apportioned among the several States and District of Columbia according to their respective Numbers, counting the whole number of persons in each State, excluding Indians not taxed, so that: The one third States having the greatest number of persons shall elect three Senators; the one-third states having the least number of persons shall elect one Senator; and the remaining states shall elect two Senators. No state shall have more than one Senator in the same Class..."
There are additional advantages to this proposal, aside from fairness. Namely, in an institution that already over-represents certain segments of the population (e.g., "red" states are over-represented currently, compared with "blue" states), this reform would (1) help mitigate the problem of the filibuster/cloture requirement, and (2) would help correct the Electoral College.
In other words, instead of just 60 Democratic votes in the 2009-10 Senate, if you used this formula, Democrats would have had at least four more. Same goes for Republican-dominated Senate in years past.
Regarding the Electoral College: If you reapportion the electoral votes based on this new formula, it more closely tracks states' actual populations. For example, even after losing Florida, under a reapportioned Senate along these lines, the popular vote winner in 2000, Al Gore, would have received enough EVs to win.
Vested interests aside, this is a no-brainer.