>>105
There are many reason's why repealing the 17th is a good thing, and it has little to do with individual state populations, which are better represented and proper in the House of Representatives, so the population argument is moot.
Excepts from Federalist Paper #62 by James Madison:
It is recommended by the double advantage of favoring a select appointment, and of giving to the State governments such an agency in the formation of the federal government as must secure the authority of the former, and may form a convenient link between the two systems.
Here, it is suggested that by giving the state legislatures the power to elect Senators, they are not only responsible to the legislatures of the states they represent (who they themselves are elected by the people), but also in an indirect way to the people. It was also because the states banded together with delegates from the original thirteen states to form the current Federal government in the first place, so it would be wise for them to also have a house in control of their legislatures.
So far the equality ought to be no less acceptable to the large than to the small States; since they are not less solicitous to guard, by every possible expedient, against an improper consolidation of the States into one simple republic.
Exactly what has happened with the state legislatures no longer holding a check on separation of powers, one could even argue that state legislatures electing Senators for their states were an additional check of power along with the rest of the Federal legislature, the Executive, and Judicial branches. Is it then any wonder why such awful legislation like the Patriot Act and such were passed? I think not.
Another advantage accruing from this ingredient in the constitution of the Senate is, the additional impediment it must prove against improper acts of legislation. No law or resolution can now be passed without the concurrence, first, of a majority of the people, and then, of a majority of the States. It must be acknowledged that this complicated check on legislation may in some instances be injurious as well as beneficial; and that the peculiar defense which it involves in favor of the smaller States, would be more rational, if any interests common to them, and distinct from those of the other States, would otherwise be exposed to peculiar dangerBut as the larger States will always be able, by their power over the supplies, to defeat unreasonable exertions of this prerogative of the lesser States, and as the faculty and excess of law-making seem to be the diseases to which our governments are most liable, it is not impossible that this part of the Constitution may be more convenient in practice than it appears to many in contemplation.
States clearly while it may have a harmful effect on passing "good" legislation, it will also be shown to be able to thwart bad legislation as well.
Second. The necessity of a senate is not less indicated by the propensity of all single and numerous assemblies to yield to the impulse of sudden and violent passions, and to be seduced by factious leaders into intemperate and pernicious resolutions. Examples on this subject might be cited without number; and from proceedings within the United States, as well as from the history of other nations. But a position that will not be contradicted, need not be proved. All that need be remarked is, that a body which is to correct this infirmity ought itself to be free from it, and consequently ought to be less numerous. It ought, moreover, to possess great firmness, and consequently ought to hold its authority by a tenure of considerable duration.
Shows the fallacy of a unicameral Federal legislature that could push potentially dangerous legislation (we see this in countries like Finland that change their constitution more than they change their underwear) through without a second house to hold a check on power of the other, further able to hold a check on power through the state legislatures that elected its members.
I would highlight more excerpts from this excellent, wonderfully worded paper, but you get the idea.
_____________________
References:
http://www.constitution.org/fed/federa62.htm