Fraud? Union thuggery? Both?
Several factors at play here. First off, the insidious reach of the teacher's unions - everyone has someone in the family or their neighbhood milking the education establishment. Secondly, the GOP overreached in passing SB5; too many parts went into one bull which was puched through the General Assembly. Had the measures in the bill been passed individually, it would have been much more difficult to repeal.
The main reason, however, was that the unions made this Ground Zero for organizing and apending money, and one part of SB5 would have done away with compulsory union membership. The unions poured tens of millions of dollars into repealing SB5, easily outspending the pro-Issue 2 group by four or five to one.
I'd bet that some of the major components of SB5 will be passed individually after the turn of the year, so the long range impact is hard to see tonight. It's not good, though.