Unfortunately, it’s not that a democrat is needed to allow the quorum. It’s that 20 people are needed, and there are only 19 there. Any warm body would do.
I suppose if they could declare these seats as abandoned, then they could run the place with just 19 pubbies until the special election replaced the missing people...
“Wisconsin is divided into 33 Senate Districts (1/3 of the current Assembly membership of 99) apportioned throughout the state based on population as determined by the decennial census, for a total of 33” — wikipedia
“2011-2012 SENATE MEMBERSHIP Republicans - 19 Democrats - 14” — http://legis.wisconsin.gov/senhome.htm
Sorry, that’s not the reason. A majority of the Wisconsin Senate is 17.