3. Children need a mother and father. The healthiest children are those reared by a married mother and father. "Marriage is the union of a husband and wife for a reason: these are the only unions that can make new life and connect children in love to their mom and dad," says Maggie Gallagher, President of National Organization for Marriage.

4. Traditional marriage is exclusive; gay unions are not. According to Dr. Brad Wilcox of the National Marriage Project, lifetime infidelity dropped in the 2000s to 16% for males and 10% for females. By contrast, according to the San Francisco Chronicle, the number of male partners of a homosexual was four per month. Is that a healthy environment in which to raise children? Some argue that gay marriage would reduce promiscuity, but two-thirds report sex outside the marriage in the first year.

5. States that passed same-sex marriage are rescinding them. After Maine's Legislature voted for same-sex marriage in 2009, Maine voters repealed the law. Subsequently, two dozen state legislators who voted for it were defeated in 2010.

6. Homosexual men are 4% of the population but account for half of all new HIV infections and 85% of syphilis cases. According to the CDC, men having sex with men (MSM) account for 48% of the one million people living with HIV, (532,000), 53% of new HIV infections (28,700).

7. HIV infections are increasing only in gay men, while decreasing among heterosexuals and drug users. MSM are the only risk group in the U.S. in which new HIV infections have been increasing since the early 1990s.

8. Homosexual men are banned from donating blood due to the likelihood they will transmit HIV and other sexually transmitted diseases. A lifetime ban has been imposed by all collectors of blood on gay men to protect America's blood supply.

9. Gay sex is a choice, and one with taxpayer consequences. Several Marylanders testifying against same-sex marriage spent years in the gay lifestyle, but changed to a heterosexual orientation and have been happily married for years. If same-sex marriage is legalized, more people will be lured into this unhealthy lifestyle. A 20-year-old gay has a 50% chance of becoming HIV positive. Many gays will seek Medicaid to cover costs of deteriorating health. It is not in the interest of taxpayers to induce more people into this destructive, costly lifestyle.

10. Gay men live 20 years shorter lives than heterosexuals, according to the only epidemiological study to date. A tenth of sexually active teens are experimenting with same-sex unions, reports a New York City study, published in the journal Pediatrics. Why encourage more teens to experiment with this destructive life style?

In summary, unlike heterosexual marriage in which fidelity is the norm for four out of five couples, promiscuity is the norm for homosexuals, even those in committed relationships. Only a tenth of gays marry if given the legal opportunity to do so. Most are not interested in marrying.

If they aren't interested, why force a change in the definition of marriage to benefit a tenth of 2% of the population? It will only encourage more sexual experimentation among young people with tragic consequences. They will live 20 years shorter lives.

For children to thrive, they need to grow up in homes with a married mother and father. In his 1828 American Dictionary, Noah Webster defined marriage as the "act of uniting a man and a woman for life," because marriage "was instituted ...for the purpose of preventing the promiscuous intercourse of the sexes, for promoting domestic felicity, and for securing the maintenance and education of children."

----Mike McManus is President of Marriage Savers and writes a syndicated column.