Marc Garneau's decision today to withdraw from the Liberal leadership race was not unexpected. If anything, the only surprise was that Garneau stayed in the race as long as he did. Perhaps he hoped for a last-minute shift in support, or that Liberals would wake up and see what he had to offer? If that was the case he was wasting his time.

One aspect of running for political office after being an astronaut is the space jokes. I admit it: I'm fond of them. "Marc Garneau: soft on gravity." "Marc Garneau: not down to Earth." "Marc Garneau: He didn't come back from space for you." (Rest assured, I did.) As I prepared to launch my campaign for the Liberal leadership, people repeatedly asked why, having been fortunate enough to enjoy a career that's taken me around the planet more than a few times, I'd want to risk my reputation on something the media has already written off as a win for someone else? This isn't rocket science.

The race to find the next Liberal leader heated up on Wednesday with Marc Garneau's entry into the fray. The MP for the riding of Westmount-Ville-Mari...