A venture capitalist who founded a company expressly to support a presidential run by Mayor Bloomberg, and who is conducting nationwide voter analysis for the mayor, says his data show that Mr. Bloomberg can win the White House.

James Robinson IV, the founder of the technology and data analysis company Symposia Group, told The New York Sun he believes that “empirically, he can win,” even with the emergence of Senator McCain as the Republican front-runner.

After starting the company in December 2006, Mr. Robinson’s team, which he says includes people at the “top of the game” in search intelligence and database analysis, spent more than nine months building a technology system that attempts to gauge the thinking of Americans on a neighborhood-by-neighborhood, and even house-by-house, basis.

He has about six full-time employees, in addition to several full-time contract employees and about 18 others who have done some work on the project since its inception, he said. Mr. Robinson said his company is mining databases and dozens of disparate data sources for the information.

“Our interest was in building some technology that would allow for a better understanding of what’s really on the minds of Americans,” Mr. Robinson said.

He is a managing partner at a venture capital firm he co-founded, RRE Ventures. He works there with his father, James Robinson III, a former CEO of American Express and the non-executive chairman of the board of directors at Bristol-Myers Squibb. Mr. Robinson said his father is not involved with his new company.

Mr. Bloomberg is paying for the Symposia Group’s work, Mr. Robinson said, but he would not disclose the specific amount coming in from the multibillionaire mayor, except to say that it is “significant.”

The mayor is “by far the biggest client and the main client,” he said. Mr. Robinson said he speaks to the mayor on occasion, but noted that most of his discussions are with the mayor’s chief political aide, Kevin Sheekey.

A spokesman at Rubenstein Communications who represents the mayor on his non-government business, Robert Lawson, declined to comment.

Mr. Bloomberg’s thinking on running for president is the topic of near-constant speculation in political circles as he crisscrosses the country speaking out on national issues such as gun control, immigration, and the environment. Mr. Sheekey told Newsweek last fall that if Mr. Bloomberg were to run, he would spend $1 billion on a campaign.

Mr. Bloomberg says repeatedly that he is “not a candidate,” but his high-profile appearances and speeches indicate he is trying to keep his options open. He did, however, deviate from his standard denial yesterday, when speaking to employees of Google at the company’s offices in the city.

After saying that he’s not a candidate for president, he went further than usual, adding that he’ll “stay that way.”

His subtle change in tone may be linked to Mr. McCain’s surge, which some political observers say makes it less likely Mr. Bloomberg will run.

Scott Rasmussen, the president of Rasmussen Reports, which conducts presidential polls, said he is fairly confident Mr. McCain will be the Republican nominee and that if Mr. Bloomberg is taking a serious look at the field right now, “he is seeing the door closing.”

Mr. Robinson said he doesn’t think Mr. McCain’s performance closes any doors, because he said he thinks Mr. McCain will have to move “uncomfortably right” to get Republicans to come out and vote for him, still leaving room for Mr. Bloomberg to enter the race.

Mr. Robinson said he thinks Mr. Bloomberg “is a very thoughtful person who is seriously considering his options.”

Mr. Bloomberg’s possible presidential aspirations appeared to take a hit yesterday when Governor Schwarzenegger endorsed Mr. McCain for president. The California governor had said previously that he would not back a candidate in the race, leading some political observers to speculate that he was holding out to see if Mr. Bloomberg jumped into the fray.

Both advocate a nonpartisan, pragmatic approach to government, and Mr. Schwarzenegger has called Mr. Bloomberg his “soulmate.”

The Associated Press reported last month that Mr. Bloomberg is conducting extensive polling and voter analysis, but did not name the research firms in the report.

When Mr. Bloomberg was later asked if he is paying for national polling data, he ducked the question, saying, “No matter how many times you ask the question, I am not a candidate.”

Symposia Group also is conducting an analysis of reports in the press and on the Internet to determine what issues voters care about. Mr. Robinson said his findings are confidential. The group built a promotional Web site, mikebloomberg.com, and maintains it for the mayor, he said.

A political strategist and pollster who has advised President Clinton and Mr. Bloomberg, Douglas Schoen, argues in a new book to be published this month that a third-party candidate could take the White House this year.

Mr. Schoen said in early January that he thought Mr. Bloomberg would decide whether to run once the nominees are selected and Mr. Sheekey has finished analyzing the field.