I REMEMBER THE SHOE BOMBER BUT NOT THESE TWO INCIDENTS

So, there are at least 3 terrorist attacks on America during the Bush years AFTER 9-11 and we still don't know who was behind the anthrax attacks. From MediaMatters:

2002 attack against El Al ticket counter at LAX. In July 2002, Hesham Mohamed Hadayet opened fire at an El Al Airlines ticket counter at Los Angeles International Airport, killing two people and wounding four others before being shot dead. A 2004 Justice Department report stated that Hadayet's case had been "officially designated as an act of international terrorism."

2006 UNC SUV attack. In March 2006, University of North Carolina-Chapel Hill graduate Mohammed Reza Taheri-azar drove an SUV into an area of campus, striking nine pedestrians. According to reports, Taheri-azar said he acted because he wanted to "avenge the deaths or murders of Muslims around the world." Taheri-azar also reportedly stated in a letter: "I was aiming to follow in the footsteps of one of my role models, Mohammad Atta, one of the 9/11/01 hijackers, who obtained a doctorate degree."