President Obama responded angrily on Saturday to the mass shooting that took three lives, including that of a police officer, at a Planned Parenthood facility in Colorado Springs over the Thanksgiving holiday, calling the country’s recurring outbreaks of gun violence “not normal.”

“We can’t let it become normal,” Mr. Obama said in a statement. “If we truly care about this — if we’re going to offer up our thoughts and prayers again, for God knows how many times, with a truly clean conscience — then we have to do something about the easy accessibility of weapons of war on our streets to people who have no business wielding them. Period. Enough is enough.”

The tragedy quickly found its way into the presidential race, with the Democratic candidates offering statements of solidarity with Planned Parenthood, which has faced intense conservative criticism this year, and the Republican hopefuls largely avoiding mention of the latest outbreak of gun violence.

Mr. Obama, who has voiced rising dismay as he has been forced to repeatedly respond to mass shootings, sounded notes of deep exasperation about yet another moment of fear and loss taking place at a time devoted to thanks and family.