NEW YORK ( TheStreet) -- The next time you receive a call from Gallup, you may want to take it seriously. Gallup, designated by the Commission on Presidential Debates (CPD) to select the five major polls that ultimately determine who may attend the pivotal election debates, allows respondents in early polling to identify their favorite presidential candidate without a predetermined list of names. This is potentially the biggest hurdle for third-party candidates who hope to make a legitimate run at the White House. "We at Gallup use several different procedures to determine which candidates to include, and part of that is empirical data -- we ask people open-endedly in each election who you are supporting," said Dr. Frank Newport, editor in chief at Gallup. Gallup's polling procedure is done totally independently of the Commission, Newport said. The catch is that for a presidential hopeful to qualify for the debates, the candidate must meet three criteria : constitutional eligibility, enough ballot access to have a mathematical chance to secure an Electoral College majority, and a level of support of at least 15%. The CPD set those guidelines last October and said the 15% support would be determined by five selected national polling organizations. The commission left it up to Gallup to choose which polls would be included. Once the five polling organizations have been picked, it is out of Gallup's and the CPD's jurisdiction as to how each organization conducts its polls. Newport offered a view of Gallup's own process. After Gallup polls people open-endedly, the organization takes several other steps to reach a conclusion on which candidates it will repeatedly mention as choices for president. "We look to see what percent of support is volunteered for a candidate to see if we're missing something," said Newport. Newport said Gallup has already done that this year and included the Libertarian and Green candidates in at least one poll to see how well they would perform in other polls when they were included by name. The next step Gallup takes is name awareness or name ID. In other words, the organization added the names of Libertarian Gary Johnson and the Green Party's Jill Stein -- both of whom have qualified to receive federal matching funds -- to see if they had any significant name ID among voters.