Um, nobody claimed the senate legalized same sex marriage.

The history of same sex marriage approval in Canada:

• The Court of Appeal in Ontario declared same sex marriage legal in 2003. It was legal in Ontario the moment that judgement was made.

• Over the next two years, eight of Canada's ten provinces passed legislation legalizing same sex marriage in their respective jurisdictions, out of recognition that the courts would declare it legal if the parliaments did not.

• In July 2005, the Canadian Parliament passed the Civil Marriage Act, which legalized same sex marriage across Canada, including in the three territories and two provinces where it had not yet been legal.

This makes the claim that Harper legalized same sex marriage to be perhaps somewhat correct, but highly misleading. It was legalized because the courts forced the federal government's hand and left the government with no other option (short of amending the Constitution)- not because Harper was a same sex marriage advocate.