The only reason Garth did it was, because of well - Garth.
He opines on his blog garth.ca, of providing "leadership through principle and independence." - but by joining the Liberals he is giving up both of those. Face it, its the Liberals who have perfected rigid party discipline. Wajid Khan was told to follow the party line or leave.
Wonder if Dion has read Turner's blog yet -
I think that's a pretty fair statement. If he was a true opponent of party discipline and that's why he left the rigid Tory caucus, he'll be an independent fast enough in the next Liberal government.