Earlier today, Connecticut’s former Secretary of State, Susan Bysiewicz, announced that she would challenge Lieberman in 2012. Although the timing might make it appear that her challenge prompted the decision to retire, it was already widely believed that Lieberman would face a strong challenge from the left. His decision to retire may have been in part motivated by the prospect of fighting an uphill battle to hold on to the seat, but the timing is more likely coincidental.