U.S. Presidential Candidates Hillary Clinton, left, and Donald Trump
U.S. Presidential Candidates Hillary Clinton, left, and Donald Trump

A collection of U.S. political surveys this week shows Democratic presidential candidate Hillary Clinton is pulling ahead of Republican challenger Donald Trump five months before November's national election.

Clinton, a former U.S. secretary of state seeking to become the country's first female president, holds an average 5.6-percentage-point lead in several polls over the real estate mogul who overtook a large Republican field of candidates, many of them current or former senators and governors, in his first bid for elected office.

All of the surveys were conducted after Clinton, the wife of former President Bill Clinton, became her party's presumptive nominee last week after a lengthy battle with her lone party challenger, Vermont Senator Bernie Sanders.

Trump, who joined the presidential race a year ago Thursday, also enjoyed growing support, at least for a time, when he became the presumptive Republican nominee in early May as his last challengers dropped out of the race.

Reactions to Orlando massacre

Almost all of the recent polling was conducted before an American-born Muslim carried out the country's worst-ever mass shooting early Sunday at an Orlando, Florida, gay nightclub, killing 49 people and wounding 53. It is not clear how the shooting might affect voters' perceptions of how Clinton and Trump would deal with such an attack as president. They responded in different ways after the extent of the carnage became known.

Police officers direct family members away from a
Police officers direct family members away from a fatal shooting at Pulse Orlando nightclub in Orlando, Fla., June 12, 2016.

Trump, calling for the U.S. to be tough on terrorists, used the massacre to renew his call to temporarily block Muslims from entering the country for fear they might commit new attacks, although the Orlando shooter was a U.S. citizen and would not have been affected by his proposal. Authorities say the shooter, killed by police as they raided the nightclub, was radicalized by jihadist tracts he saw on the internet.

Clinton denounced Trump's anti-Muslim plan and his call to build a wall along the U.S.-Mexico border to halt undocumented immigrants from entering the United States.

"I don’t know how one builds a wall to keep the internet out," Clinton said. "So not one of Donald Trump’s reckless ideas would have saved a single life in Orlando. It’s just more evidence that he is temperamentally unfit and totally unqualified to be commander-in-chief.”

Muslim cooperation essential

Clinton, the top U.S. diplomat from 2009 to 2013, said, "We rely on partners in majority-Muslim countries to help us fight terrorists. We need to build trust in Muslim communities here at home to counter radicalization in the lone wolf phenomenon.”

Imam Azhar Subedar, left, speaks during a special
Imam Azhar Subedar, left, speaks during a special interfaith prayer service at the American Muslim Community Center in Longwood, Florida, June 13, 2016, to support the Orlando shooting victims.

Numerous Republican establishment figures have given Trump tepid endorsements, even as they have often criticized his call for the Muslim ban and now his response to the Orlando mass shooting. Others, like 2012 Republican presidential nominee Mitt Romney, have rejected Trump's candidacy, saying his views do not represent the party's traditional conservative policies and that his caustic comments denigrating women, war heroes, Mexicans, Muslims and others are unacceptable for a presidential candidate.

On Thursday, Richard Armitage, a deputy secretary of state under Republican President George W. Bush, told the Politico news site that he is voting for Clinton, saying that Trump "doesn't appear to want to learn about issues."

Trump said this week that if key Republican officials do not support his candidacy, "I'll just do it very nicely by myself."

The latest CBS News poll showed Clinton ahead of Trump, 43 percent to 37 percent. With Libertarian presidential candidate Gary Johnson added to the mix, Clinton polled at 39 percent among registered voters, with Trump at 32 percent and Johnson at 11 percent.

Also this week, a Bloomberg News survey showed Clinton with a 49 percent-to-37 percent lead over Trump, with Johnson at 9 percent. An NBC News/Survey Monkey tracking poll pegged Clinton's edge at 42-38 over Trump and Johnson at 9 percent, while a Guardian/SurveyUSA poll had the race with Clinton at 39 percent, Trump at 36 percent and Johnson at 6 percent.