Nicole Bengiveno/The New York TimesThe Conservative Political Action Conference opened with the Pledge of Allegiance on Thursday morning in Washington.

This year’s Conservative Political Action Conference, being held in Washington Thursday through Saturday, will welcome back several key organizations that had boycotted the annual festival because it had allowed a conservative gay group to be listed as one of many co-sponsors.

David Keene, the former chairman of the American Conservative Union, which puts on the event, had justified the participation of the gay group, GoProud, saying it was important to “give an umbrella for all groups that are legitimately conservative on most issues.”

But implacable opponents of same-sex marriage and endorsement of homosexuality, including the Family Research Council, Concerned Women for America, Liberty University (founded by the late Jerry Falwell) and even the Heritage Foundation shunned the meeting, saying that a group working to undermine one of their core values should not have a place at the table.

Senator Jim DeMint, Republican of South Carolina, also declined to attend, expressing support for the boycotters, while Mike Huckabee, the former Arkansas governor and evangelical leader stayed away without saying why.

Mr. Keene stepped down at the 2011 meeting, and the new chairman, Al Cardenas, a prominent Florida Republican and lawyer, along with a reshaped board of directors, decided to bring these conservative stalwarts back into the fold, excluding GoProud for any sponsorship role. The major boycotting groups are back as sponsors and in the agenda. Mr. DeMint and Mr. Huckabee are both speakers.

On Monday, a sponsorship controversy of a different sort emerged. Bloomberg.com reported that Google was listed as one of the primary sponsors of the meeting — the only business so listed, along with, for example, the National Rifle Association and the Heritage Foundation. In a message e-mailed to Bloomberg, Google said that it has plans to have a presence at political events this year because they tend to attract young people who are savvy about technology.

“This event is a great opportunity for us to showcase Google.com/elections and tools like Google+, which we hope will be used by every candidate and campaign,” the company said. “We’re planning hangouts with top Republicans and well respected conservative journalists at CPAC,” the e-mail said.

The liberal advocacy group People for the American Way quickly pounced, with a widely e-mailed message titled, “Does Google Know It’s Sponsoring a Right Wing, Anti-Gay Conference?”