<p>In this April 6, 2016 file photo, Democratic presidential candidate Hillary Clinton speaks in Pittsburgh. Fifty-five percent of Americans say they have a negative opinion of Democratic front-runner Hillary Clinton. But thatís not nearly as bad as how they view the leading candidate for the Republican nomination, Donald Trump. (AP Photo/Keith Srakocic, File)</p>
Hillary Clinton says electing Donald Trump president would be a "historic mistake" for the United States.
The likely Democratic nominee for president is casting Trump as thin-skinned, irrational and unprepared to be commander in chief.
She says his vision for America is "all wrong." She is urging voters to remember that the U.S. is a "big-hearted, fair-minded country."
Clinton's comments came in a foreign policy speech that held her most blistering criticism to date of the presumptive Republican nominee for president.
The remarks signal that Clinton won't hold back in challenging the billionaire businessman's readiness to be president in the general election.
Copyright 2016 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.