According to a new CNN poll, how you ask Americans about gay marriage determines their level of support. But on average, a slim majority of Americans support the institution.

CNN's poll asked about gay marriage with two different questions.

In the first question, proposed to half of those polled, 49 percent said they are in favor of gay marriage, but the figure jumped to 52 percent in the second version.

Forty-nine percent of respondents agreed with the question: “Do you think gays and lesbians have a constitutional right to get married and have their marriage recognized by law as valid?”

But the question, “Do you think gays and lesbians should have a constitutional right to get married and have their marriage recognized by law as valid?” fared better, with a majority of respondents (52%) agreeing.

“Combining the two subsamples has 50.5 percent of Americans in support of gay marriage and 47.5 percent opposed: just about the barest possible majority,” statistician Nate Silver wrote on his blog at FiveThirtyEight.com. “But a majority nevertheless, something that no previous poll had shown.”

Evan Wolfson, executive director of Freedom to Marry, a group that promotes the adoption of gay marriage laws throughout the U.S., lauded the breakthrough.

“For the first time, a national poll shows that a majority of Americans support the freedom to marry and that those who would deny liberty and equal protection to same-sex couples are in the minority,” Wolfson said. “Americans are realizing that gay couples crave the personal significance of marriage and need the critical safety of protections and responsibilities that marriage brings.”

Pollsters began their survey on August 6, two days after a federal judged declared California's gay marriage ban unconstitutional. The poll has a margin of error of 4.5 percentage points.