WASHINGTON - Slipping in some recent polls, short on campaign cash and facing a mini-rebellion from disenchanted Republican delegates, presumptive presidential nominee Donald Trump took his best shot Wednesday at turning his political fortunes around with a full-throated attack on presumptive Democratic nominee Hillary Clinton.

Clinton has moved into a lead in several recent national polls in the wake of a difficult period for Trump that includes fundraising woes and a weakened campaign infrastructure in need of a tuneup.

Trump sought to open a new chapter Wednesday with a salvo aimed at Clinton that began with his contention that she is a “world-class liar” who was a failure as secretary of state.

“No secretary of state has been more wrong, more often and in more places than Hillary Clinton,” Trump said to cheers during a speech in New York City. “Her decisions spread death, destruction and terrorism everywhere she touched.”

Trump added that Clinton “may be the most corrupt person ever to seek the presidency,” and that her immigration policies were dangerous for the country and would amount to a “mass amnesty.”

Democratic U.S. presidential candidate Hillary Cli
Democratic U.S. presidential candidate Hillary Clinton, left, and House Minority Leader Nancy Pelosi, a California Democrat, leave a House Democratic Caucus meeting on Capitol Hill in Washington, June 22, 2016.

Clinton's condemnation

Clinton shot back during a campaign stop in North Carolina on Wednesday. She said Trump was attacking her personally, including her religious faith, as a distraction. She said she thought his answers to tough campaign issues had no substance.

One day earlier, Clinton had railed against Trump, calling into question his reputation as a successful businessman and warning he would be reckless and a risky choice for the country.  

“Every day, we see how reckless and careless Trump is," Clinton said Tuesday. "He’s proud of it.  Well, that’s his choice — except when he’s asking to be our president.  Then it’s our choice."

Vice President Joe Biden was also on the attack against Trump during a speech in Washington this week, blasting the Republican's renewed call for a temporary ban on Muslims coming into the United States in the wake of the mass shooting in Orlando, Florida.

“ISIL wants to manufacture a clash of civilizations," Biden said, using an acronym for the Islamic State group. "They want Americans to view things in terms of ‘us versus them.’  Why in God’s name are we giving them what they want?”

Massachusetts Senator Elizabeth Warren, a potential vice presidential pick for Clinton, also joined in the Trump-bashing during a recent speech to Democrats in New Hampshire.

"Every day it becomes clearer that he is a thin-skinned, racist bully. And every day it becomes clearer he will never be president of the United States,” she said.

Trump struggles to unify  

By focusing on Clinton, Trump hopes to resume his quest to unite the Republican Party behind his candidacy and ease doubts among some within his party that he cannot make the transition from primary contender to general election candidate.

Trump told supporters at a recent rally in Phoenix that the tensions between his campaign and the Republican establishment stemmed from his decision to run as a political outsider.  

“As soon as I ran, I became an insurgent. I became an outsider,” Trump said.  “And you know why?  Because I am going to do what is right for you. I am not going to do what is right for them!”

Many Republican leaders remain critical of Trump, but few have abandoned him.  

“Yeah, they can’t trust Trump and they also can’t trust him to pursue their priorities if, in fact, he is elected,” said University of Virginia analyst Kyle Kondik. “I think Republicans are making the calculation that in a battle of two ‘lessers’ [of two evils], they would go with the one who at least has their party label.”

Pressing for a makeover

Others are surprised at Trump’s struggles to shift from a Republican primary campaign to a general election showdown against Clinton.  

FILE - A Donald Trump supporter, left, and a prote
FILE - A Donald Trump supporter, left, and a protester argue before the candidate's arrival in West Chester, Ohio, March 13, 2016. Democratic and Republican views of the opposing political party have sunk to such lows that many say their rivals make them feel afraid, according to a Pew Research Center poll released June 22, 2016.

“I’ve always thought that some of Mr. Trump’s rhetoric works very well for [Republican] primary audiences, but it is going to cause him a larger problem, potentially, in the fall,” said longtime national political reporter Tom DeFrank of the National Journal.

Many Republicans believe Trump has some work to do in transforming himself into a viable general election candidate.  

“He needs to broaden his appeal to better engage the American public, give them a vested interest in his election,” said Republican analyst and author Scot Faulkner, a veteran of the Reagan administration who also worked in the House under former Speaker Newt Gingrich. “He’s certainly tapped the outrage.  Now he needs to tap the idealism.”

The pressure on Trump to shift into general election mode also comes at a time when a small group of disenchanted Republican delegates is trying to find a way to derail his nomination before or during next month’s Republican National Convention in Cleveland.

Analysts have doubts

Spurred on by Trump's recent controversies, the anti-Trump forces say the movement is growing, though many analysts remain skeptical that Trump’s nomination will be undone in Cleveland.  

“I think that is wishful thinking in the extreme,” DeFrank said on VOA’s Issues in the News program. “But the fact that more and more Republican leaders are very nervous about him leading their party into November, that is unquestionably true.”

Current polls give Clinton an advantage for the general election. But those same surveys also show a desire for change, not uncommon after a two-term presidency. That yearning for change, even if there is a risk attached, could eventually help Trump.  

Interfaith religious leaders protest against Repub
Interfaith religious leaders protest against Republican U.S. presidential candidate Donald Trump outside a hotel where he was to meet with evangelical leaders in New York City, June 21, 2016.

“There is this utter desperation and sense of many Americans that not just that our system is broken, but that they keep trying to deliver messages to Washington and Washington doesn’t listen,” said Lara Brown of the Graduate School of Political Management at George Washington University.

A recent Quinnipiac University poll found Trump running about even with Clinton in two key swing states, Ohio and Pennsylvania, while Clinton had a sizable lead in another key battleground state, Florida.

Trump’s best chance to reset his campaign may come at the convention, assuming that what is now a small brushfire rebellion of disenchanted delegates doesn’t grow into something more threatening over the next few weeks.