"The notion that he would attack a Gold Star family that made such extraordinary sacrifices on behalf of our country, the fact that he doesn't appear to have basic knowledge of critical issues in Europe, the Middle East, in Asia, means that he's woefully unprepared to do this job," Obama said of Trump on Tuesday.Obama also criticized Trump's fellow Republicans for not taking a stronger stance against the candidate."I don't doubt their sincerity. I don't doubt they were outraged by some of the statements that Mr. Trump and his supporters made about the Khan family," Obama said, speaking of Republican leaders, a number of whom spoke out against Trump's remarks about the Khan family. "But there has to come a point in which you say, 'Somebody who makes those kinds of statements doesn't have the judgment, the temperament, the understanding to occupy the most powerful position in the world.'"The president also noted that Trump has made plenty of gaffes and offensive remarks while on the campaign trail. "There has to be a point at which you say, 'Enough,'" Obama said.