My understanding of the Founding Fathers decision to elect Representatives and Senators in a different manner is that it was to serve as a check and balance. They were not going to have a House of Lords and a House of Commons (and look at how that changed), but they saw the need for representation for both the average citizen, and for the wealthy. The tyranny of the inner city voting bloc is no better than any other tyranny. It is possible that electing Senators by state legislators would still be a problem. In the more rural states, it would result in a different kind of Senator being elected. The history of politics in the US shows that there has always been an attempt by the large cities to control everything in the country, and this has been resisted by the people living outside of the cities. And, we aren’t the only country with this conflict. The Khmer Rouge forced all the people out of the cities in Cambodia to relearn the truths of an agrarian lifestyle. Their solution was to put plastic bags over the heads of the city people who disagreed with them.
Not only possible, but definitely. The Texas example on the GOP side alone, nevermind what Illinois, Massachusetts, California, et al, would produce on the Democrat side (and that there would be zero chance of anything Republican getting elected). Corruption and unaccountability was already an epidemic problem by the 1910s. The makeup of a Senate under a repealed 17th with an even more elitist and corrupt ultraleft Democrat membership, combined with a "moderate milquetoast RINO" big gubmint contingent would make a bad situation even worse.