President Donald Trump used a prime-time address to the nation Tuesday to insist on $5.7 billion for a steel wall along the Mexican border that he said would stop the shedding of "American blood" by illegal immigrants. The nine-minute speech from the storied Oval Office in the White House contained no concessions to Democrats refusing to fund construction of the wall -- a project Trump has made his signature domestic policy idea. Trump spoke in an unusually measured voice, apparently hoping to claim the moral high ground, and said he wanted to bridge the political divide in what could be the defining power struggle of his turbulent presidency.