When it comes to his presidential opponent, Republican Donald Trump wants to #LockHerUp. Democratic nominee Hillary Clinton's supporters are standing their ground days before the election, declaring #ImWithHer.

More than in any previous presidential election, experts say, social media are playing a key role in the fight for voters' hearts and minds. About 44 percent of U.S. adults learned about the presidential election from a social networking site, according to a survey by the Pew Research Center this year.

Town halls and rallies are still important, but the front lines in the battle for the White House are shifting as more people consume news on social media.

"Social media is more of a doorway to the rest of the campaign. You get your hardcore supporters to follow you on Twitter and Facebook, and the goal from that point is to get them to share your stuff with their friends," said Laura Olin, who was the social media director for President Barack Obama's 2012 re-election campaign and now works at marketing consultant Precision Strategies.

"A message they get from their friend is more compelling then a message they would get from a campaign."

From January to October, 109 million Americans on Facebook generated 5.3 billion likes, posts, comments and shares about the election, according to the company. Campaigns are also tapping into the audiences on Twitter, Snapchat, Instagram, YouTube, Pinterest, LinkedIn and other sites.

But voters are skeptical about the information they read on social media, and some political scientists question how effective the flurries of text, photos and videos are at swaying undecided voters. When discussing politics with someone who doesn't share the same views, about 59 percent of social media users found it stressful and frustrating, while only 35 percent found it interesting and informative, a recent Pew survey found.

Some voters, such as San Ramon resident and actress Kristina Teves, try to stay away from sharing their political thoughts on Facebook because the conversations get too heated, especially among family and friends.

"I feel like we've turned our democracy into some sort of sporting event, where you pick your team and even if they're losing, you want to support them," said Teves, who grew up in a conservative family but is voting for Clinton.

After seeing a clip of first lady Michelle Obama's speech at the Democratic National Convention on Facebook, though, Teves couldn't stay silent any longer. "When they go low, we go high," Obama said, after referencing "hateful language" from public figures on television.

The remarks resonated with how Teves felt about all the partisan bickering, so she posted publicly about how voters should "check your sources, keep an open mind before you angrily shout into the void and remember to respect everyone regardless of their opinion."

Some voters say they're taking social media posts with a grain of salt, raising questions about whether candidates' messages are getting lost in the din.

"I feel like there's a little bit of disillusionment that has crept in," said Steven Weber, a professor at UC Berkeley's School of Information and Department of Political Science. "We expect people to spend too much time reading what they already agree with. We expect crazy tweet storms that very few people pay serious attention to other than when they're absurd and make people angry."

Nonetheless, Trump's barrage of late-night tweets has shaped the campaign in ways previously unseen in a U.S. presidential election. His controversial missive suggesting former Miss Universe Alicia Machado appeared in a sex video was brought up during the second presidential debate, where Trump was asked if the tweet demonstrated the discipline of a good leader.

"Tweeting happens to be a modern-day form of communication," Trump responded. "I mean, you can like it or not like it."

But it's not just words that are grabbing voters' attention. More social media users have been consuming recorded and live video on these websites, giving candidates opportunities to interact with voters in ways they haven't in previous election cycles. Both Twitter and Facebook live-streamed the presidential debates.

Don Seymour, Facebook's U.S. politics and government outreach manager, said that elections campaign staffers are doing a lot more on social media than in the past.

"Today, the people who use Facebook successfully or see the best results are folks who use it as a platform to connect with voters and actually have more of a two-way conversation," said Seymour, who worked as a communications director for former House Speaker John Boehner.

Candidates have used Facebook to broadcast rallies live, show behind-the-scenes footage, showcase endorsements from other politicians, conduct Q&As, raise funding and more. Last week, Trump's campaign launched a nightly news program on Facebook Live, including a link to donate money. He raised $9 million from a pair of live videos that resembled news programming at the final presidential debate, Politico reported, citing data provided by the Trump campaign.

And both Twitter and Facebook have been trying to boost voter turnout. Twitter users who sent a direct message to @gov with their ZIP code received their state's voter registration deadline and a link to register. Facebook also started reminding U.S. users 18 years and older to register to vote, a feature that helped more than 2 million users do so, the company said.

"Facebook really is the new town hall, and we're proud of the role that we've played in enabling dialogue and increasing civic engagement," Facebook CEO and co-founder Mark Zuckerberg said in a conference call Wednesday after the tech firm released its quarterly earnings.

Social media have cast the public spotlight on the opinion of some voters, such as photographer Brandon Stanton -- who wrote one of the most shared posts in Facebook's history when he posted a letter to Trump -- and Ken Bone, the undecided voter who became an internet sensation after asking a question on energy policy during the second presidential debate.

Still, stories like Bone's and Stanton's are rare, and some local voters are choosing to keep quiet while others can't resist giving their two cents.

San Jose resident Landon Kupfer, 21, hasn't decided who he's going to vote for but is leaning toward Trump after learning about his policies. Kupfer, who refrains from talking politics on Facebook, watches live videos of the candidate's rallies but chooses not to comment.

"With all the thousands of comments they have posted every second ... I don't feel like my voice will be heard until I cast my vote," he said.

Kevin Seal, a 41-year-old Castro Valley resident and a Clinton supporter, is active on both Twitter and Facebook. "There are times when I'll try to bite my lip and not say anything," he said, "but I have a difficult time restraining myself."

Seal also admits he's probably not swaying any votes with his social media comments.

"I honestly don't think I'm convincing anyone of anything," he said. "I don't think it's really my intent. I think it's searching for community and fellowship in a way."