Setting the stage for a fight with the two leading Democratic presidential candidates and the frontrunning Republican, Mayor Bloomberg is railing against the recently passed federal economic stimulus package, saying that handing out checks to stimulate the economy is “like giving a drink to an alcoholic.”

Mr. Bloomberg said the candidates are looking for simple solutions to long-term, systemic economic problems.

“This country has a balance sheet that’s starting to look more and more like a Third World country,” Mr. Bloomberg said, speaking to reporters at a public school in Harlem yesterday. “And we are trying to protect jobs, rather than enhancing the skill sets of our workers so that they can take the jobs of the future.”

No one wants to admit there’s “no easy solution” to the country’s economic problems, he said.

“They want to send out a check to everybody to stimulate the economy. I suppose it won’t hurt the economy, but it’s in many senses like giving a drink to an alcoholic,” he said. “The government’s been doing exactly that. It’s been spending money it doesn’t have, and that’s one of the reasons our economy is in trouble.”

President Bush on Wednesday signed the $152 billion stimulus bill, which calls for 128 million households in America to receive tax rebates of $300 to $1,200. Senator McCain, the Republican front-runner, voted in favor of that bill; the Democratic presidential hopefuls, Mrs. Clinton and Mr. Obama, missed the vote, but voted earlier in favor of an expanded version of the stimulus plan. The idea is to stimulate the economy by putting cash in the hands of Americans and hoping they spend it.

Mr. Bloomberg, a multi-billionaire who founded a financial services company, Bloomberg LP, before running for mayor, has criticized Washington lawmakers for their reliance on deficit spending and warned last month that America is “going to mirror a third world country pretty soon” with the debts it is piling up.

Although Mr. Bloomberg denies he is a candidate for president, he is paying for a national analysis of voters, according to the owner of the company doing the analysis. A political strategist who has worked for the mayor, Douglas Schoen, says there a system in place to get Mr. Bloomberg on the ballot in all 50 states.

Mr. Bloomberg’s possible presidential prospects received a boost yesterday from Robert Shrum, a Democratic strategist who ran presidential campaigns for Senator Kerry and Vice President Gore. The strategist said he thinks there is a “very good chance” Mr. Bloomberg would run for president, but only “against the right other two candidates.”

“I always thought that under the right circumstances in a three-way race, of course he could win,” Mr. Shrum said during an interview yesterday on NY1, according to a partial transcript provided by the station.

“This is someone who has been in elective politics and has worked with political professionals, and has some very smart people around him. And he’s tough-minded, can make decisions, but doesn’t think he knows everything. And that’s an important gift in politics,” he said.

Some political observers have argued that Mr. Bloomberg’s opening to run as a third-party candidate closed when Mr. McCain shot to the front of the Republican pack. Mr. McCain, they say, appeals to the same centrist voters Mr. Bloomberg would be trying to attract if he ran.

Mr. Bloomberg yesterday had a few kind words for Mr. Obama, saying he deserved credit for talking about the country’s infrastructure. But the mayor used a question from a reporter about Mr. Obama’s plan to spend $60 billion on such projects to note his own focus on national infrastructure and calls for more federal infrastructure funding.

“I don’t know whether Senator Obama looked to see what I’ve been advocating, or not, you’ll have to ask him, but he’s doing the right thing,” he said.

Mr. Bloomberg’s work to crack down on the illegal sale and trafficking of guns also may garner a wave of national attention in the coming weeks.

On Wednesday, he announced that the city was working to build a regional database for East Coast cities to track guns used in crimes.

Yesterday, a gunman opened fire in a lecture hall at Northern Illinois University, injuring at least 18 students before killing himself.

He fired from a shotgun and two handguns, the Associated Press reported.