FARMINGTON HILLS, Michigan, Sept 19 (Reuters) - A

star-studded virtual event hosted by Oprah Winfrey Thursday

night to build enthusiasm for Kamala Harris' campaign was marked

by teary moments and celebrity endorsements, drawing hundreds of

thousands of viewers across social media.

Winfrey hosted the "Unite for America" event with activist

group Win with Black Women, that aimed to register people to

vote and bolster Harris in states such as Pennsylvania, Georgia

and Michigan that are set to decide the Nov. 5 election.

Shanette Williams, the mother of Amber Nicole Thurman, a

28-year old Georgia woman who died in August 2022 after a

hospital treatment delay related to the state's restrictive

abortion laws, told the audience: "You're looking at a mother

that is broken, the worst pain ever that a mother, that a parent

can ever feel."

Harris responded: "I'm just so sad. And the courage that you

all have shown is extraordinary." Many in the studio audience of

about 400 were in tears.

Natalie Griffith, a 15-year-old student from Apalachee High

School in Georgia who was shot twice while in math class two

weeks ago, sat with her parents in the front row.

"What are we doing?" asked Natalie's mother, Marilda

Griffith. "We have a job, that job is to protect our children.

We have to stop it," she said, as she and some in the audience,

virtual and in-person, cried.

Harris and Democrats have promised to restore national

abortion rights impacted by a 2022 Supreme Court decision and

pass a ban on assault weapons often used in mass shootings.

Celebrities including comedians Chris Rock and Ben Stiller

along with actors Julia Roberts, Meryl Streep and Bryan Cranston

joined the event and offered their reasons for backing Harris or

peppered her with questions.

"I want to bring my daughters to the White House to meet

this Black woman president," Rock said.

Winfrey noted Harris' swift transformation after President

Joe Biden stepped out of the race in late July, lauding Harris

for "stepping into her power."

"You know we each have those moments in our lives when its

time to step up," Harris said. Before Biden was forced out,

Harris' strength as a presidential candidate was questioned by

some Democrats in Washington, including Biden. But she has

revived Democrats' chances, bringing in new fundraising and

enthusiasm.

Harris had an unguarded moment, when Winfrey said she was

unaware that Harris was a gun owner until her debate with

Republican opponent Donald Trump.

"If somebody breaks in my house, they're getting shot,"

Harris said. "Probably should not have said that," she added.

Harris campaign advisers say nearly 200,000 people signed up

to watch the livestream, and its YouTube audience was nearly

100,000 by the end. Instagram, Facebook, Tiktok and Twitch

accounts for both Winfrey and Harris also showed the event.

Dozens of grassroots groups including Latinas for Harris,

White Dudes for Harris and Win With Black Men that held virtual

organizing and fundraising calls in the days after Harris became

the Democratic nominee and Thursday marked the first time they

all joined in one event.

In a recent Reuters poll, Harris led Trump 47% to 42%.

Harris was ahead in the battleground states of Michigan,

Pennsylvania, Wisconsin, Nevada and North Carolina, while Trump

had greater support in Georgia, according to polling averages

from aggregator FiveThirtyEight. They are tied in Arizona.

"And while we have this extraordinary growing enthusiasm

that the Vice President and Governor Walz are seeing everywhere,

we are still in a margin of error race. It's tied. It's tied

right here in Michigan. It's tied in all the battleground

states," campaign chief Jen O'Malley Dillon told the crowd.

Earlier Wednesday, pro-Palestinian grassroots organization

the Uncommitted National Movement which has a large presence in

Michigan, announced it was not endorsing Harris, even as the

group said it also opposes Trump and does not encourage votes

for third-party candidates.