A Williams Institute on Sexual Orientation Law and Public Policy study (PDF) released Wednesday shows the number of same-sex couples in America has dramatically increased since 2000. The study, based on the Census Bureau’s new American Community Survey (ACS), shows a 30 percent increase in same-sex couples between 2000 and 2005 — nearly five times the six percent growth rate of the U.S. population. The increased numbers are most likely not from a greater number of gay people beginning relationships, but the increased willingness of same-sex couples to identify as such.

When the census statistics were being collected in 1999 and 2000, it was still illegal to have gay sex in several states (until the Supreme Court overturned sodomy laws in 2003). It had been a little over a year since Matthew Shepard was tied to a fence in rural Wyoming and several years before same-sex marriage was believed to be a realistic goal for equality. But in the years between the 2000 census and the most recent ACS survey, much happened that has radically changed LGBT people and their role in society. Gay and lesbian relationships have been used by presidential and Congressional candidates as a weapon for mobilizing anti-gay voters. Same-sex marriage has been legalized in Massachusetts and the Supreme Court ruled in favor of gay and lesbian people in Lawrence v. Texas. These events have encouraged same-sex couples to live their lives more openly and honestly, which is part of the reason we see the tremendous increase in same-sex couples between 2000 and 2005.

In six of the eight states with anti-marriage equality amendments on the November ballot, the number of same-sex couples has increased more than the national average of 30 percent. The number of same-sex couples in Wisconsin has increased by 81 percent since 2000, Colorado by 58 percent and South Carolina by 39 percent. Although these numbers are unlikely to dramatically affect the outcome of these ballot initiatives, they could make moderate politicians reconsider their positions on these amendments. Support for anti-gay amendments will alienate a larger number of people than the 2000 statistics would suggest, and in close races, it could make a difference in whether a politician wins an election.

The Williams Institute study estimates there are 8.8 million gay, lesbian and bisexual (GLB) Americans and that there are same-sex couples in every Congressional district in the United States. Although the study shows GLB people make up only 3 percent of the U.S. population, the actual number is likely higher because of the number of GLB people who are closeted or did not identify as GLB in the ACS survey. These numbers can make an important voting bloc in elections that are growing increasingly tight in recent years.

As statistics on gay and lesbian people continue to become more accurate, the impact of sexual orientation and gender identity issues on elections will become increasingly evident. While the average American voter feels less threatened by the possibility of same-sex marriage, gay and lesbian people are continuing to come out and become an influence in American politics.