Hillary Clinton plans to address America’s leadership in the world during a speech in the battleground state of Ohio, arguing that Republican nominee Donald Trump would undermine the country’s greatness while she would maintain it.

Clinton’s midday address at the American Legion’s annual convention in Cincinnati Wednesday comes as Trumpplans a last-minute trip to Mexico hours before he delivers a long-expected speech on immigration. A Clinton campaign official said the Democratic nominee will use her first public event in days to portray her Republican opponent as a questionable leader who would “walk away from our allies, undermine our values, insult our military – and has explicitly rejected the idea of American exceptionalism.”

In contrast, Clinton will “make the case” for American exceptionalism, an idea that the U.S., as an “exceptional” world citizen, has a moral obligation to advance democracy in the world rather than imposing it against another country’s will. Clinton has long promoted pro-democracy projects in countries interested in changing their government and in her speech will “call for maintaining America’s military and diplomatic leadership in the world,” the official said.

Her views differ from Trump, who in his foreign policy speech, called for the U.S. to seize Iraq’s oil, its major source of income and one of its few natural resources. “To the victor goes the spoils,” he said.

Trump has pledged to “Make America Great Again” and restore the country to a time when, in his view, the U.S. was more prosperous and full of opportunity.

Clinton is pitching to Republicans who might support her that she will better support the military, foreign relationships and American values. She will talk about her experience on the Senate Armed Services Committee and as secretary of state.

A campaign official said that another Republican national security expert would back Clinton. James Clad, former deputy assistant secretary of defense under President George W. Bush, will announce his support for Clinton, following a slew of other GOP endorsements from the national security world. In a statement, Clad says that “giving an incoherent amateur the keys to the White House this November will doom us to second or third-class status.”

Clinton’s speech in Ohio comes after several days of big-ticket private fundraisers in the Hamptons, a wealthy community on New York’s Long Island, where she collected millions at waterfront mansions in preparation for the fall campaign. The fundraising swing concluded in style Tuesday night, with an event featuring performances from Jimmy Buffett, Jon Bon Jovi and Paul McCartney.

Though many national and state polls show Clinton with an edge, she has been stressing that the campaign must not take anything for granted. At a fundraiser on Monday she told supporters she was “running against someone who will say or do anything. And who knows what that might be.”