I LOVE the idea of wise State legislators appointing Senators to look after the interests of their States.
The reality is that, by 1900, the State legislatures were already hopelessly mired in corruption and graft. Some legislatures couldn't appoint a Senator for months or years at a time because nobody could make the payoffs.
When you look at the quality of actually existing State legislatures, you would NEVER agree to give them more powers.
And when you look at the quality of actually existing U.S. Senators, Democrat and Republican, including The Most Revered and Holy Savior, moderate Scott Brown, you would NEVER agree to give them more powers, either. And yet, in 1913, we did just that with the 16th and 17th Amendments. They now have the power to hoodwink millions of people into re-electing them again and again, as well as appropriate endless amounts of money taken out of our paychecks.
And as far as direct elections goes, the U.S. House has passed both Cap and Tax and Health Care Deform in some form, so as far as elections vs. appointments goes, let's just say, the jury may still be out on that one. And if the legislators are really this horrible and corrupt, guess what, that means the PEOPLE have failed to keep THEM in check.
I wouldn't say "wise," but more responsive to people, who would find it easier to travel to the state capital, rather than to DC, if political intransigence demands it. The legislators tend to cover smaller groups of people than U.S. Congresspeople, too, as I understand it, (an exception of note is California state senators -- each one covers about 800,000 people, compare to about 700,000 for each U.S. Congressman) which, at least in theory, would enhance their responsiveness to people.