See post #40. Also, some links provided show the complaint itself and some relevant information regarding the 2/3 requirement.
ANother poster said that "exceptions have been made" to the 2/3 requirement, but he did not elaborate on what the exceptions were, nor did he indicate that it had any bearing here.
Maybe he'll respond.
Wouldn't have been me (hadn't been to the thread when you wrote this), but the only constitutional exception to the 2/3 requirement is that a proposed tax increase, once it passes the legislature by a simple majority, first gets placed before the voters in the next general election. If it's approved there by a majority vote, it then takes effect.
The SCON added a second, unconstitutional exception; when the legislature first approves drunken-sailor spending without authorizing funding for bloated school budgets and the governor refuses to let the legislature rethink their choice of bottles.