In Virginia, where Thomas Jefferson's influence was strong, the 1776 constitution had no two-thirds vote on this issue. Not until 1829, three years after the death of Jefferson, was the rule for conviction on impeachment changed by constitutional amendment to two-thirds. Similarly, Vermont's 1793 constitution had no two-thirds rule until it was changed by constitutional amendment in 1836. There is no evidence to support that view. From the beginning in 1784, any changes had to go through an approval process as designated by the constitution, and every super-majority vote in our constitution has gone through that process.
Nothing can be further from the truth.
No impeachment trial ever challenges a branch of government. Only individuals in the branches are subject to the impeachment process for misconduct in office. What the Senate did was to attach a completely novel interpretation without documentation for its view. Traditionally the New Hampshire Bar Association has been the public defender of the court in New Hampshire, especially since the adoption of Part II, Article 73-a, in 1978. Under this amendment the Supreme Court has expanded its authority over a unified bar with its power of rule-making.