The issue focused much of Monday night's heated presidential debate between Democrat Hillary Clinton and Republican Donald Trump.Clinton sought to outline what she sees as Mr Trump's hypocrisy over comments about Mexican immigrants and rape and pilloring disabled veterans.Mr Trump questioned Mrs Clinton's qualifications for office and questioned whether she could handle classified information."Can she handle classified information?" asked Mr Trump.Mrs Clinton answered by describing herself as "someone who cares deeply about security".Trump tweeted after the debate that Mrs Clinton should resign because she cannot handle classified