Washington - After an emotional debate over how to keep Americans safe, the Senate Thursday narrowly defeated an effort to prevent civilian trials in U.S. courts for the accused planners of the 9/11 attacks.

The Senate's 54-45 vote to reject the measure by Sen. Lindsey Graham, R-S.C., opens the door for President Barack Obama to bring Khalid Sheik Mohammed, the self-professed mastermind of the Sept. 11, 2001, attacks, to trial in federal court, rather than the military commissions Graham helped create.