Time to amend the Constitution?
Article 1, Section 3, Clause 4
The Vice President of the United States shall be President of the Senate, but shall have no Vote, unless they be equally divided.
Sixty votes is the new normal. For any legislation that reaches a floor vote, the Senate will never "be equally divided".
No, it only matters when Democrats hold the majority. If the Republicans should hold 51 seats then we're back to the days of majority rules. Of course, that also implies they'd be solid with 60, with the Blue Dogs providing the extra 10 at least. And if the Democratic wing should get to 60, then the 70 seat line will become the rule for "matters of national concern".
Damn, now I need a drink.