ST. LOUIS — Mayor Bloomberg’s demand yesterday that politicians go beyond “cheap platitudes” and offer real solutions for improving public education at the National Urban League’s annual conference is expected to raise the bar for the 2008 presidential candidates who will speak there tomorrow.

Mr. Bloomberg, who says he has no plans to run for president himself, was greeted with a standing ovation just two days before the three leading Democratic presidential candidates, Senators Clinton and Obama and John Edwards, and two lesser-known Republicans candidates appear at a political forum here.

He told the group that politicians have been pandering by saying fixing public education is only about more money and smaller class sizes.

“They’ve given us cheap platitudes and slogans instead of real solutions,” Mr. Bloomberg said during an impassioned speech to National Urban League leaders in a downtown hotel ballroom.

The blunt speech zeroed in on the achievement gap between white and minority students and offered a slew of details about educational priorities he regularly talks about in New York. And the mere fact that Mr. Bloomberg traveled 950 miles to attend a conference hosted by a prominent group devoted to African-American economic issues raised more questions about whether he is planning to enter the race for the White House.

While speculation has been rampant in the five boroughs about whether his hyped-up national travel schedule is a clue that he wants to run, in the Midwest, many people haven’t heard much about him. In that regard, this trip served the important purpose of introducing him to African-American leaders.

During his speech, Mr. Bloomberg singled out Mr. Obama for becoming the first Democratic candidate to offer “moderate support” for bonus pay for teachers, a concept that has met union resistance in New York.

The mayor later said: “I would like to see all of the candidates on both sides of the aisle focus on how they would improve public education. It’s easy to say, ‘I’m in favor of better public education’; nobody is going to say they aren’t.” Then he added: “Just tell us how you’re going to do it.”

Mr. Bloomberg echoes that thought in an interview set to air on “Good Morning America” today: “Nobody’s willing to say explicitly, “This is what I believe. This is how I would improve education, for example,” he tells interviewer Robin Roberts.

The mayor’s focus on the inequality in education and fulfilling the promises of the civil rights movement, which he cited twice, seemed to resonate with the audience, which offered loud applause when he called the absence of advanced placement courses and gifted and talented programs in certain communities a perfect example of “the soft bigotry of low expectations.”

He also won over the crowd when he said teachers should be offered financial incentives to work at lower performing schools and called paying more effective teachers more money “Management 101.”

“Those who don’t perform up to standard, you let go,” he said. He said locked-in pay scales that don’t recognize talent “didn’t work in the Soviet Union, and it’s time for us to recognize that it’s not working in our schools.”

The president of the National Urban League, Marc Morial, praised Mr. Bloomberg for setting out his positions in front of the group.

“What the African-American community wants is competition for our vote,” he told The New York Sun. “We don’t want to be taken for granted.”

A poll of New York City voters released by Quinnipiac University yesterday showed that 53% of respondents think speculation about Mr. Bloomberg running for president is good for the city, but only 34% said they would “definitely” or “probably” vote for him if he ran.

Fifty-five percent of respondents said Mr. Bloomberg’s businesslike approach to government would give him a boost in a national campaign, and 25% said it would not make a difference.

Voters still overwhelmingly approve of Mr. Bloomberg’s job performance as mayor, although the overall percentage of supporters has slipped to 73% of respondents from a record 75% in a January 16 poll.