Crime doesn’t seem likely to be a huge issue in this year’s Republican primary. But friends of Giuliani were wondering whether his record on crime in New York City would continue to shine when the book was closed on Mitt Romney’s four years as governor of Massachusetts.

When the FBI offered its tabulation of crime statistics for 2006 last month, criminologists were finally able to compare a full four year term with another four year term. And the statewide crime rate numbers for Massachusetts from 2002 to 2006 are mixed, significantly behind the dramatic drop in crime rates from either term of the Giuliani era.

First, to establish the baseline of Giuliani’s success in New York, in his first four years, every category dropped dramatically: murder down 60.4 percent, robbery down 48 percent, aggravated assault down almost 28 percent, burglary down 45 percent, forcible rapes down 23.4 percent, larceny down 33.2 percent, and car theft own 53.8 percent.

Over Giuliani’s full two terms, murder rates dropped 66 percent, forcible rape dropped 45.7 percent, robbery dropped 67.2 percent, aggravated assault dropped 39.6 percent, burglary drooped 68.1 percent, larceny dropped 43 percent, and motor vehicle theft dropped 73.3 percent. This was during a time period when the population of New York City grew 9 percent.

During Romney’s governorship, the numbers we mixed, moving modestly in either direction. Murders actually increased 7.5 percent, robberies increased 12.25 percent, and burglaries 5.8 percent. Rapes dropped almost 2 percent, aggravated assault dropped 14 percent, larceny dropped 6.63 percent, and motor vehicle theft dropped 32.4 percent. The state population barely changed, rising .15 percent.

In Boston, the picture is a little grimmer, although one can argue how much crime on the streets of Boston is the responsibility of Romney and how much is that of Democratic Mayor Tom Menino. In Boston, from 2002 to 2006, murder increased 25 percent, robbery up 6.5 percent, aggravated assault up 12.29 percent, burglary up 7.6 percent. The good news was that forcible rapes dropped about 25 percent, larceny declined 5.2 percent and car theft dropped 42.5 percent.

With the drop in New York City’s crime rate so central to Giuliani’s image, it was unlikely any of his rivals would try to claim the crime-fighter mantle, and the saliency of the crime issue at the presidential level is unclear today. (Would the Willie Horton ad be as effective today? Would any Democratic candidate feel compelled to authorize an execution during the campaign the way Bill Clinton did in 1992?) Still, Giuliani and his backers can point to recent crime statistics and crow, “no, not everybody can do what we did.”

UPDATE: Brian Faughnan thinks I’m being unfair to Romney:

The first one you point out — the Mayor of New York has more influence over crime fighting in New York City than the Governor of Massachusetts has over crime fighting in Boston. It’s unclear what share of the credit or blame should go to Menino, and what share to Romney.
But second, to compare New York in the 1990s to Boston in the 2000s is apples and oranges. Whether due to changing demographics, improved police tactics, or sunspots, most large American cities saw falling crime rates in the 1990s. That was apparently the case in Boston as well.
Let’s assume for the sake of argument that Boston had its dramatic crime reduction in the same time frame as NYC had its own. If that turns out to be the case, then it’s probably not fair to say that Romney — who came along after the reduction — was less effective. The same would be true of Bloomberg, for example. If Giuliani (or Governor Weld, or Tom Menino) wrung all the possible improvement out of the system, then there was less room for Romney to make progress.

Well, notice these are percentage comparisons, not absolute numbers. If I reduce the number of murders in my city from 100 to 50 during my term, the next guy only has to reduce it to 25 to equal that fifty percent reduction. Yes, maybe I took the low-hanging fruit in the first fifty, but he only has lower the remaining number of murders by a smaller absolute number to equal the reduction rate.