Both -- likely following the advice of their campaigns -- took the safe road by avoiding the politically polarizing subject altogether.
But if the savage assault is cause for Americans to come together to mourn, why can't we stay together long enough for a rational discussion on gun violence?
Please, spare me the sermons on Second Amendment rights. No one -- especially this rifle-and-shotgun-shooting daughter of Virginians -- is suggesting pulling guns away from law-abiding citizens.
Still, after Colorado and Virginia Tech and the almost-assassination of former Rep. Gabby Giffords, we ought to be able to separate the issue of gun ownership from that of gun violence. And figure out what to do about it.
Consider this: One of the four weapons recovered in the theater on Friday -- even as desperate families begged police for information about loved ones whose bodies were still in the building -- was an AR-15 assault rifle, the civilian version of the M-16.
The AR-15 was covered under the old federal assault weapons ban. So were large magazines of ammunition. The goal, back then, was to slow the number of guns capable of quickly killing large numbers of people on the street.
In the five years before the ban, so-called assault weapons made up 4.82 percent of the crime gun traces conducted by the federal Bureau of Alcohol, Tobacco, Firearms and Explosives.
During the ban's lifetime -- from 1995 to 2004 -- the weapons made up 1.61 percent of guns the ATF traced to crime, according to a 2004 report from the Brady Center to Prevent Gun Violence, a 66 percent drop from the earlier rate.
Those numbers, no surprise, began to rise again after the ban expired in 2004, according to officials.
It's too early to know -- if we'll ever know -- why James Holmes, a failing neuroscience PhD student, planned an assault that killed 12 and injured at least 70 at a midnight showing of "The Dark Knight Rises," according to authorities.
One congressman lamented that no one else in the theater had a gun to take down a suspect who had protected his head, throat, chest, groin and legs with black military SWAT-like gear.
New York Police Commissioner Ray Kelly would add to the description later by saying that Holmes -- who legally owned all four guns recovered at the scene -- painted his hair red and identified himself to police as Batman's archenemy "The Joker."
As a friend observed on Friday, you can't stop crazy but you can try to slow crazy down. Which is why Bloomberg and McCarthy repeatedly stand up against gun violence.
"I don't know what kind of tragedy we have to live through anymore," said McCarthy, who lost a husband and almost lost a severely wounded son in the 1993 LIRR massacre.
"The American people get upset," she said, "and then forget about it."