Illinois Rep. Tom Morrison, a Republican, has defended comparing gay marriage to polygamy and statutory rape.

Morrison made the comparisons in an email to a constituent.

“If one male and one female is discriminatory, then isn't limitation of marriage to just two people discriminatory, too?” Morrison wrote. “There are men who would like to marry two or more consenting females. Would you define their relationship as marriage, too? Could a man marry a consenting 9-year old girl? Why not? To refuse them would be discrimination. Again, where would you draw the line?”

A bill which seeks to legalize such unions in Illinois awaits action in the House after passage in the Senate.

Kathleen Betts told Talking Points Memo that she sent her initial email in an attempt to appeal to Morrison's “sensibility for equal rights.”

Morrison apologized to Betts in a subsequent email but he also defended his stance.

“The point I was trying to make was this: the state already has certain restrictions on what marriage is,” Morrison wrote. “The law itself makes distinctions on who can and cannot marry. For example, one cannot be married to more than one person at the same time. You are not advocating for polyamory (I don't think), but there are those in Illinois who do. Just google Polyamory Chicago, and see for yourself. They argue that the state is discriminating against their sexual orientation, love, desire to commit, freedom, equality, etc. …”

“Changing a law like this is not a light matter. Same sex relationships have been around for millenia, obviously, but codifying marriage as a relationship without regard to gender is a shift of enormous proportions. Interracial marriages have been in existence for millenia, too. Though they were temporarily (in the scope of human history) outlawed in certain jurisdictions, the unions were still of man and woman. That's why I don’t believe it's appropriate to say SB10 is analogous with interracial marriage laws, by the way.”

(Related: Illinois Rep. Jeanne Ives says gays trying to “weasel their way into acceptability.”)