Austin City Coucil Takes a Conservative Stance?

The Austin City Council, widely accepted as being very liberal thinking when devising policies, made a surprise decision recently. A proposal that would consolidate the 2012 elections to November was voted down 4-3. Proponents for keeping the Council elections in May hid behind the mandates of the city charter, among a veiled humility that extending current terms 6 more months wasn't within their purview. This article in the Austin American Statesman outlines the story Austin City Council.
I struggle understanding why such liberal elected officials would use such conservative reasoning for thier stance. The cost difference in consolidated elections in November versus Council elections in May then all the rest in November is half a million dollars. The recession has created such a huge city deficit that it seems unreasonable to throw away money unnecessarily. This, however, isn't their true motivation.
May elections occur roughly in conjuction with final exams, making it difficult for students to be active participants. And, even if able to vote in an election, should a run-off occur, voters have to wait to cast another ballot in June. Most students chose to return home for the summer, leaving an abysmally low turnout. On the other hand, the activists who remain in Austin consistently show up for every election. This has the air of protecting their Council seat as incumbants rather than the "my hands are tied" argument.
There is also a division in the City Council, where more practical liberals such as Mayor Leffingwell and Councilman Martinez are at odds with the very liberal Kathie Tovo and Sheryl Cole. When an election occurs in a wide electorate, candidates whose views are closer to the middle of the road fare better than those who hold to the extreme. With the 4-3 advantage in votes currently, the very liberal can work to keep the electorate small in hopes of keeping the majority of votes needed to pursue their agenda.
Austin has taken the course, through its elected officials, of being this enrgy conservative, bike riding, city of the future. So, why in a city that\s trying to ban plastic bags in grocery stores, is the City Council taking such a cnservative stance against the greater good?