Let's not forget that Obama also mentioned handgun violence in his hometown of Chicago.
His disdain for firearms covers a lot more than just one class of firearms.
You’re right, Obama is against handguns, also. These are Obama’s actions prior to the White House.
Obama:
In 1996, signed issues statement supporting banning all handguns
In 2000, co-sponsored a bill to restrict buying handguns to 1 per month.
In 2004, voted against a bill protecting a homeowner if they had to use an illegal gun to defend against a home invasion
In 2005, voted against a bill protecting gun manufactures and dealers from civil liability for guns later used in crimes.
In 2008, supported the D.C. handgun ban argued in Heller vs. D.C.
http://www.ontheissues.org/2012/Barack_Obama_Gun_Control.htm
Romney:
Endorsed by the NRA. Also backed by GOAL, the Gun Owners Action League in Massachusetts who states:
“During the Romney Administration, no anti-Second Amendment or anti-sportsmen legislation made its way to the Governor’s desk. Governor Romney did sign five pro-Second Amendment/pro-sportsmen bills into law. His administration also worked with Gun Owners’ Action League and the Democratic leadership of the Massachusetts House and Senate to remove any anti-Second Amendment language from the Gang Violence bill passed in 2006. A summary of this legislation follows.”
(The “assault weapons ban” that Romney signed as Governor was actually BACKED by the gun lobby there because it LOOSENED the existing restrictions.)
http://www.goal.org/newspages/romney.html