New York Mayor Michael Bloomberg’s definition of political independence is shaped by his unusual status as a multibillionaire. Bloomberg in effect operates as his own party, rewarding principled acts of rebellion with his own considerable resources. (Spencer Platt/Getty Images)

It may seem odd for New York Mayor Michael R. Bloomberg to take the national lead in advocating for gun control one day, and endorse a National Rifle Association-approved Republican the next. But Bloomberg has his own method.

On Wednesday, just three days after Wade Michael Page killed six people at a Sikh temple, Bloomberg explained at a news conference why he supports Republican Sen. Scott Brown over gun-control advocate Elizabeth Warren (D) in the Senate race in Massachusetts — and it came down to their shared opposition to a specific concealed-weapons bill: “I asked him to stand up and go against his party,” Bloomberg said. “He is much more an advocate of the NRA than I am. . . . [But] Scott Brown did what we needed him to do, and for that reason I said I would support him.”

It’s all part of Bloomberg’s definition of political independence, which is shaped by his unusual status as a multibillionaire. Witness his contributions to the four (endangered) Republican state senators in New York who provided crucial support for same-sex marriage, which Bloomberg backed; or, for that matter, his subsidies to Republicans who let him run for reelection on their line, even after he abandoned the party.

Bloomberg in effect operates as his own party, rewarding principled acts of rebellion with his own considerable resources. For this Democrat-turned-Republican-turned-independent, whose national policy pronouncements are usually pox-on-both-houses denunciations of Washington, overarching party goals are beside the point.

“Both candidates for president should speak out” about gun control, Bloomberg remonstrated as he stood in a police surveillance center in downtown Manhattan on Wednesday. As dozens of video panels showed footage of the city’s streets and data such as “Bronx: Shots/Fired” streamed behind him, he asserted, “This is one of the great national problems that we have. People are dying.”

Bloomberg is a data-driven despot who denounces soda, directs hospitals to hide infant formula because it could distract new mothers from breast-feeding, and defends Chick-fil-A and the so-called 9/11 mosque. In his mind, supporting a general opponent of gun control who came through for him on one critical measure is not inconsistent or hypocritical. It’s good business.

But does the Bloomberg method work?

As exhibit A, Bloomberg has pointed to the influence he was able to exert as the largest donor to the state’s Republican caucus in persuading some critical state GOP lawmakers to back his goal of legalizing same-sex marriage.

After explaining his support for Brown, he said, “I did exactly the same thing with some Republicans that stood up for gay marriage.”

But those same Republican state senators have also blocked key gun control legislation that he supports, perplexing advocates of gun control who think the most effective way to achieve their mission is to elect more Democrats.

New York state Sen. Michael Gianaris, while laudatory of Bloomberg’s efforts to combat gun violence, said, “I cannot speak to why he chooses to support Republicans who are at odds with his policy initiatives.”

When Bloomberg took his gun-control message on a national TV tour, turned it into a national TV ad and hinted that he might pour enough money into his Mayors Against Illegal Guns organization to potentially bother the National Rifle Association, liberals nationwide applauded his courage. And then he endorsed Brown, and they didn’t know what to make of him. Rank-and-file Democrats have taken to characterizing the Bloomberg method, and his endorsement of the Wall Street-friendly Brown, as old-fashioned political hypocrisy.

After the mayor’s news conference near Wall Street, some of the city’s leading Democrats gathered on the steps of City Hall for a rally with New York Sikhs to express solidarity in the wake of the Wisconsin shooting.

“When you position yourself to be a national voice on an issue that is plaguing cities across the country, you don’t have the luxury of talking out of both sides of your mouth,” the city’s comptroller, John Liu, said as the rally broke up. “It’s not just Scott Brown, it’s members of our own state legislature here in New York. It’s congressional candidates across the country. He’s being a politician and he’s getting credit for an issue he doesn’t have any control over.”

Bill de Blasio, the city’s public advocate, asked “why on Earth” Bloomberg would back a candidate who can’t even support the assault weapons ban in “a state like Massachusetts, where it clearly is within the mainstream of public interest.” He also said Bloomberg’s support of Brown could lead to a Republican majority in the Senate that will be stridently against gun control. “I can’t square that.”

Bloomberg officials argue that the notion of supporting Democrats to get anything done on guns is wrong because Democrats don’t do anything on guns. As evidence, they cite a call between the mayor’s point men and Warren’s policy team, which the Bloomberg officials said showed no interest in pushing opposition to the concealed-gun bill.

The Bloomberg team also thinks its strategy is effective. Brown is actually in office. The assault-weapons ban is essentially dead. President Obama hasn’t shown any leadership, and Democrats in Washington have not brought up for vote other gun issues dear to the mayor.

That paralysis has led some lifelong Democrats to believe that those who don’t see the wisdom of Bloomberg’s way are essentially clad in partisan blinders.

“He is the only major political figure in America operating outside the two-party system and as a result, he sometimes makes decisions that partisans don’t understand,” said Deputy Mayor Howard Wolfson, who fought for years in the Democratic trenches for Chuck Schumer and Hillary Rodham Clinton. Wolfson argued that although gun control is a critical issue for the mayor, he is not a single-issue advocacy group. He also cares deeply about immigration and public health and the financial sector — issues that at times put him in line with Democrats and then at others with Republicans.

Insisted Wolfson: “The independence is in service to accomplishments.”