Clinton, Trump court the undecided as campaign grinds on

White House frontrunner Hillary Clinton and her Republican rival Donald Trump slogged on to secure votes in key battleground states Friday as their nasty, brutal campaign entered its final weekend.

Clinton is slightly ahead in national polls as the nearly two-year race approaches its climax, and many Americans will be relieved in four days when the bad-tempered spectacle is over.

A Gallup poll published Friday found that less than half of voters feel that the candidates are talking about the issues that matter to them, and both have historically low approval numbers.

Investors are not happy with their options: Wall Street was down again Friday despite relatively good news on the jobs front, with the US S&P 500 slipping for the ninth straight session, its longest fall since 1980.

Where enthusiasm is lacking, the 69-year-old former secretary of state and the 70-year-old property mogul are trying to manufacture it, or at least rile up their supporters against the other side.

"I need you to vote. Don't choose fear, choose vote," an exasperated President Barack Obama told a mainly African American crowd in North Carolina, whipping up votes for fellow Democrat Clinton.

Intervening to stop the crowd booing a pro-Trump protester, he resorted to the new campaign catchphrase he uses to signal his mounting disbelief: "C'mon!"

"I want you to pay attention. If we lose focus, we could have problems," he said, deriding Trump's outbursts as those of a crude reality television star beneath the dignity of the presidency.

"And the problem is he's done it so much that it's become almost normal," Obama said. "It's like suddenly reality TV has entered the race for the presidency.

"It's just some stuff that up until this election we would have said is completely disqualifying and yet somehow everybody's gotten accustomed to it, acting like it's normal."

- Swing state bingo -

While Obama may be annoyed by the intrusion of Trump's pop culture star power into the race, Clinton clings to A-listers like a lifeline -- later Friday, she is to make a joint appearance in Ohio with rapper Jay Z and perhaps his wife Beyonce, after stops in Pennsylvania and Michigan.

Trump, meanwhile, was to swing through the swing states of New Hampshire, Ohio and Pennsylvania touting his plan to "drain the swamp" of corrupt politicians to his supporters.

He is not expected to mention that two aides to his top ally New Jersey Governor Chris Christie were found guilty on Friday of deliberately causing major traffic jams to punish a political rival.

Both candidates are also saturating the airwaves with ads -- mainly negative ones -- and dialing the scare rhetoric up to fever pitch.

Clinton's campaign will reach a crescendo in Philadelphia on Monday, where she will appear with Bill Clinton and Barack and Michelle Obama -- a union of Democratic Party power families.

Voters can expect to hear not-so-kind comparisons between Trump and the still-revered US founding fathers, who made their Declaration of Independence in the city, and later signed the US Constitution there.

The tone of the race certainly was less than high-brow on Friday.

"Imagine what it would mean for our economy to have someone who built his career exploiting workers, stiffing small businesses," Clinton said in Pittsburgh.

Trump, in New Hampshire, fired back: "How can Hillary manage this country when she can't even manage her e-mails?" referring to the ongoing controversy over her set-up at the State Department.

Pennsylvania voter Frank Behum, who spent 32 years working as an electrician for a steel plant before retiring, said the choice at the ballot box on November 8 was not ideal.

"You've got to pick the lesser of the two evils here," he said.

Clinton's supporters were getting tense.

"It's nerve-racking that Trump's gotten this far," Rachel Zeolla, 27, who works in creative marketing, said at Friday's rally in Pittsburgh.

- Republicans coming home -

The campaigns are still jostling for supremacy in the handful of battleground states that will decide Tuesday's election.

Trump has the slenderest of leads in New Hampshire, is up 3.3 points in Ohio and trails by three points in Pennsylvania, according to poll aggregates compiled by RealClearPolitics.

Trump has struggled to recover ground since footage emerged of him boasting of committing sexual assault and a dozen women came forward to allege he had groped them.

But, as the race nears its conclusion, profound Republican skepticism about his controversial candidacy appears to be ebbing.

"I think Republicans are coming home," Congressman Jason Chaffetz told CNN.

Most polls still suggest he is the outsider, but in a race full of unusual twists, a Chinese monkey described as the "king of prophets" has tipped him to win.