Ninety years ago, Walter Lippmann wrote about the "manufacture of consent," in his classic work "Public Opinion." The general idea was that public opinion was becoming increasingly susceptible to manipulation by elites.

Most people today don't have time to deal with the complexities of issues. Instead, they tend to take cues from the media and what they assume others are thinking. Especially in climates of fear, public opinion is less a reflection of what people really believe than it is an operative nudge to elicit approval or disapproval among the public.

This is clearly the case today as the shroud of political correctness suppresses open debate and aligns with the manipulation of polling numbers to push forward a perception of plausibility for a most implausible idea: same-sex marriage.

Hart Research Associates recently reported a big polling shift toward support for same-sex marriage in Maryland, 54 percent to 40 percent.

Gleeful bloggers and news editors from Maryland Juice to the New York Times created celebratory headlines.

But it may be too early for media's same-sex marriage proponents to start popping champagne corks.

Last spring, just prior to a similar vote in North Carolina, highly regarded Public Policy Polling reported 55 percent - 41 percent in favor. Same sex marriage went down in flames there, 61 percent to 39 percent -- a huge 16 point discrepancy between polling and balloting.

Polling data is easily manufactured through intensive campaigns by special interests such as the gay marriage lobby. Such data are then publicized and repeated to create a false illusion of collective belief. This is known as an "opinion cascade."

White House regulatory czar Cass Sunstein and economist Timur Kuran once wrote a Stanford Law Review article on this topic, referring to a cascade as "a self-reinforcing process of collective belief formation by which an expressed perception triggers a chain reaction that gives the perception increasing plausibility through its rising availability in public discourse."

Poll numbers, celebrity endorsements, politically correct media hype and other forces work together to shut up those who disagree with same-sex marriage and to construct an illusion of much broader support than exists. Once individuals perceive social punishment for expressing a dissenting view, they often clam up, and thereby aid the cascade. But such a process creates fragile support.

Perhaps the reality of that fragility is beginning to hit home. The LGBT oriented Washington Blade recently posted on its website a database of the names and addresses of Marylanders who signed the petition calling for a referendum on the state's same-sex marriage law. Many were shocked to find the names of family members, friends and neighbors. One reader commented, "Apparently a lot of people didn't realize their signatures would be made public. This brings into question the validity of recent polling data."

Although a majority of Americans easily express openness to some form of recognized unions for pollsters, same-sex marriage has been defeated in every one of the 32 states where it has been put to popular vote. So far, the argument that gay marriage is a civil rights issue consistently loses out to trepidation over the surrender of a venerable institution, marriage.

And that's grounds to expect that this Maryland referendum may not be such a slam-dunk after all.

Doug Mainwaring and Stella Morabito are freelance writers who both testified in Annapolis against same-sex marriage legislation which is subject to a referendum in Maryland this year.