It's a paradox worth reflecting on: in a city where Democrats outnumber Republicans five to one, New York is entering its 16th year of Republican mayoral governance-eight years under Rudy Giuliani and now another eight under Michael Bloomberg.

The Republican Party has taken a stand for good government by putting its mayoral ballot line to pragmatic use, running the electable, if not mainstream Giuliani and the even more unorthodox Bloomberg. Voters weary of the Democratic Party's consistently old-line mayoral candidates, and eager to avoid a return to New York's Bonfire of the Vanities days, have found the Republican lever something of a release valve. All New Yorkers, particularly those of Democratic persuasion, owe the city's Republican Party a debt of gratitude.

With the November 2009 mayoral election looming, the leaders of New York City's Republican Party have opened their ballot line to Bloomberg again as he pursues a third term - even though he declared himself an Independent in 2007, with an "undeclared" eye toward a possible presidential run. Allowing Bloomberg back into the party may not have been an easy pill to swallow for rank and file Republicans, but it's a measure of his effectiveness in office. Still, securing the Republican line isn't enough; he'll need Republican votes as well. To win a third term, he must secure a super majority of New York City's half million Republicans, and convince 700,000 other registered voters that he deserves a third term as New York's mayor.

Of course, just running for a third term required that Bloomberg surmount another obstacle: the city's term-limits law, a hard-won legislative victory particularly popular among Republicans. Ron Lauder, New York's champion of the terms-limits legislation that unintentionally but necessarily put Rudy Giuliani to pasture in the wake of September 11thendorsed a special, one-time pass for Bloomberg. Lauder cited Bloomberg's financial-sector expertise and expressed his worry that the other mayoral candidates would lead the city back to the service cuts and looming bankruptcy of the 70s. Lauder and other New York political leaders considered Lehman Brothers collapse last fall, and the financial meltdown that followed, and concluded that the city would be well served if Bloomberg could keep his hat in the political ring. Last fall, Bloomberg won a City Council vote extending the term-limits law.

So now Republicans, Independents, and Democrats will have a chance to weigh Bloomberg's political bona fides and judge whether they warrant a third term. They can start with some facts:

• Under Bloomberg, crime is at its lowest rate in over 40 years, dropping nearly 30% since he took office.

• He's cut the welfare rolls by 120,000 and is willing to stand firm against those who argue that tough economic times should mean eliminating the work requirement for public benefits like food stamps.
  

• His post-9/11 counterterrorism efforts have been Herculean, yet they go largely unmentioned. Bill Bratton, who now heads up the LAPD, refers to New York City's counterterrorism operation as the "Gold Standard." Today over 1,000 NYPD officers-stationed both here and in hot spots around the world-wake up every day with the purpose of disrupting terrorist plots against the city. Working with the FBI, they have exposed at least seven planned attacks.

• Giuliani railed for years about the dysfunctional Board of Education, but it was Bloomberg who won mayoral control of the schools, and the numbers speak for themselves: graduation rates are up by 22 percent, and the number of students meeting state standards is up 15 percent in English and 30 percent in math. Dozens of failing schools have been closed and 354 new ones opened, including 63 charter schools. School crime is down by 34 percent.

Those who oppose Bloomberg for his departures from Republican orthodoxy, or even his rebranding as an Independent, should remember the mayor's track record in maintaining and expanding the reforms Giuliani first put into place. It was obvious from the beginning that Bloomberg did not fit neatly into mainstream liberal or conservative molds. The label "Independent," in fact, best fits his political philosophy.

I understand the reservations of Republican Party regulars. I'll continue to have policy differences with the mayor myself. Michael Bloomberg is not the spot-on, central-casting choice for my political philosophy. But even when he veers off course, the mayor usually fits Ed Koch's self-description of a "liberal with sanity." If that distinction is lost on some readers, it's probably because the past 16 years of Republican mayoral rule have kept liberal madness on the margins.

In the end, Republicans need only ask one fundamental question: "If the election were held tomorrow, and in light of the problems that threaten our city, who is the best choice to lead New York: Bill Thompson or Michael Bloomberg?" The answer is clear. Republicans, as well as the other four-fifths of the electorate, should get behind the best public servant we have and send Michael Bloomberg back to the mayor's office.