The issue of same-sex marriage has provoked a civilizational clash between the religious and the non-religious or anti-religious. Overwhelming majorities oppose gay marriage among those who define themselves as religious, oppose common law unions, worship at traditionalist churches, and report having had few rather than many sexual partners (4 or fewer). Support for gay marriage tends to be stronger among those who define themselves as non-religious, report having had five or more sexual partners, attend liberal rather than traditional congregations, and belong to the small minority who favour polygamy.

More moderate divisions of opinion separate men from women, who are marginally more favourable to gay marriage, Francophones, who are somewhat more supportive of gay marriage than Anglophones, the under-30 cohort from older cohorts, which tend to oppose gay marriage, immigrants such as Muslims, Hindus, and Sikhs from nth generational Canadians, who are more favourable to gay marriage rights, and the highly educated (two degrees or more), who are more sympathetic to gay marriage than are other educational strata.

Respondents were asked whether they agreed with a series of arguments presented for and against gay marriage rights. A long overdue need to protect homosexuals against discrimination was the argument that resonated most with Canadians, even among those who opposed gay marriage.

Only one anti-gay marriage argument resonated with the public, albeit barely—the idea that gay marriage is an insult to religion. Most respondents did not agree that gay marriage insulted parenthood, offended common sense, or could lead to polygamy. Among the political parties, the Conservatives have by far the most to gain from the issue for a series of reasons:

• The Liberal and NDP electorates are divided on the issue but the Conservative electorate is almost unanimous in its opposition to gay marriage;
  
• Among voters who are passionate on the issue—take firm positions or say that same-sex marriage is an important issue for government to address—those who oppose gay marriage are far more numerous than those who favour it;
  
• the proportion of the electorate opposed to gay marriage is larger than the Conservative share of the vote;
  
• a large majority, including most Liberals, favours resolving the marriage issue by referendum, a traditional Alliance/Conservative party form of deliberation; and
  
• normally Liberal-voting immigrants tend to embrace the Conservative party position on the issue.
  
  

The main opportunity for gain by the Liberals would depend on their ability to persuade the electorate that Conservative opposition to proposed legislation is rooted primarily in homophobic attitudes.

On the main issues, Canadians have remained virtually unchanged in their views since late 2003. Most still do not embrace gay marriage. There is a hint that the minority embracing the change may have increased, albeit only slightly if at all.

On the specific matter of polygamy, about a third of the public believes that same-sex marriage will hasten the arrival of plural marriage but most do not have such a perception. About an eighth actually favours polygamy for Canada.