WASHINGTON — President Donald Trump has a vision for his second term, if he wins one, of establishing a “National Garden of American Heroes” that will pay tribute to some of the most prominent figures in U.S. history, a collection of “the greatest Americans to ever live.” His idea, conveyed in a speech Friday night at Mount Rushmore and expanded on in an executive order, comes as elected officials and institutions are reckoning with whether it is appropriate to continue to honor people, including past presidents, who benefited from slavery or espoused racist views, with monuments or buildings and streets named after them. Absent from Trump’s initial list are any Native American or Hispanic individuals.