Why was Israel spared scrutiny for the 1967 USS Liberty attack?

On June 8, 1967, at least 34 US sailors were killed and 171 wounded in an Israeli attack on the USS Liberty, a US Navy technical research ship stationed in the Mediterranean off Egypt's Sinai Peninsula. Israel claimed mistaken identity, but survivors and researchers dispute this. This year, the attack has renewed attention after US Representative Thomas Massie announced a speech on the House floor to honor the USS Liberty crew.