WASHINGTON (REUTERS) - Democratic presidential front-runner Hillary Clinton pivoted to a general election matchup against Republican candidate Donald Trump on Thursday, saying he is dangerously unpredictable and not qualified to be president.
Confident that she is finally close to defeating US Senator Bernie Sanders of Vermont for the Democratic nomination, Clinton turned heavy fire on Trump, who has been running about even with her in national polls of voters looking ahead to the Nov 8 presidential election.
On the Republican side, Trump promoted top aide Paul Manafort to serve as campaign manager and chief strategist, the Trump campaign said. Corey Lewandowski, the trusted Trump aide who has had the title of campaign manager, will continue overseeing day-to-day operations, the campaign said.
In a CNN interview, Clinton used the example of the apparent downing of an EgyptAir plane from Paris to Cairo to say that Trump would lack the skills to bring together US allies to respond to global threats.
"I know hard this job is, and I know we need steadiness, as well as strength and smarts in it, and I have concluded that he is not qualified to be president of the United States," Clinton said.
Trump, the Republicans' presumptive presidential nominee, has been intensifying his criticism of Clinton by lobbing personal attacks at her and her husband, former President Bill Clinton.
Clinton, a former US secretary of state, said she would resolutely refuse to respond to Trump's goading. "He can say whatever he wants," she said.
But she said the EgyptAir crash reinforces the need for American leadership and that Trump's proposed temporary ban on Muslims entering the United States has sent the wrong signal to countries that Washington will need to work with in the fight against Islamic militants.
"He says a lot of things that are provocative, that actually make the important task of building this coalition, bringing everybody to the table and defeating terrorism more difficult,"she said.
"It sends a message of disrespect and it sends a message that makes the situation inside those countries more difficult."
Trump stepped up efforts to rally Republican loyalists behind his campaign after winning a divisive primary fight that left the party ruptured.
On Capitol Hill, Manafort and other Trump aides met with conservatives in the House of Representatives who are members of the Freedom Caucus group and canvassed them for policy ideas.
"Manafort was reaching out for ideas" on policy, and several Freedom Caucus members made suggestions, said Republican Representative Scott DesJarlais of Tennessee.
"It went very well, it was encouraging. I think the Trump team recognises the relevance of the Freedom Caucus, and the influence they have. I think actually, despite some early scepticism by some members, I think the (Freedom Caucus) board received Manafort and his representation of Trump very well,"DesJarlais said.
US House Speaker Paul Ryan, who met Trump a week ago to try to resolve differences over their approaches to key issues, said he thought a list of 11 potential Supreme Court nominees, a group of conservative jurists announced by Trump on Wednesday,"was a very good step in the right direction."
Ryan told reporters that "our teams are meeting" to talk policy, and "we're making progress, but that's all I've got to say at this point."
The highest-ranking House Republican woman, Representative Cathy McMorris-Rodgers, said she had cast an absentee ballot for Trump in Washington state's primary next week, leaving Ryan as the only top Republican in Congress who has not backed Trump.