Triumphantly armed with a majority of his party's delegates, Republican Donald Trump unleashed a broadside attack Thursday on Hillary Clinton's prescriptions for energy, guns, the economy and international affairs, shifting abruptly toward the general election with his likely Democratic opponent locked in a divisive primary contest. The New York billionaire shrugged off signs of discord within his own campaign hours after sewing up the number of delegates needed to clinch the GOP nomination, a feat that completed an unlikely rise that has upended the political landscape and set the stage for a bitter fall campaign.