Toronto Star: With a snap spring election virtually out of the way, Liberal Leader Stéphane Dion faces what could be a make-or-break decision for his next campaign. Over the next few weeks, he will have to decide whether and when to firm up plans to make a carbon tax a centrepiece of the Liberal platform. For Dion, the pros of campaigning on a notion he initially rejected as a leadership candidate are potentially as irresistible as the cons of promoting a tax in an election are daunting. A …