'Start Here': Trump's mixed messages on China trade war and escalation of violence in Hong Kong protests

Here's what you need to know to start your day.

It's Monday, Aug. 26, 2019. Let's start here.

1. Second thoughts?

"Yeah, sure," Trump told reporters. "I have second thoughts about everything."

Just hours after the president appeared to take a softer tone toward China, White House Press Secretary Stephanie Grisham attempted to clarify his remarks, saying Trump's words were "greatly misinterpreted" and he "regrets not raising the tariffs higher."

Treasury Secretary Steven Mnuchin suggested Trump had misheard the question and told ABC News Chief White House Correspondent Jonathan Karl that higher tariffs aren't on the table, "But if China retaliates again, that's obviously an option the president can consider."

The mixed messages have added to the uncertainty surrounding the president's economic policies as allies at the summit warned him about the global ramifications of his trade war.

2. Hong Kong chaos

Police in Hong Kong fired warning shots and used tear gas in Sunday clashes with thousands of pro-democracy protesters, some of whom hurled bricks and hard objects, marking an escalation of violence in the city.

Dozens of demonstrators were arrested and 15 officers were injured in the chaos, according to police.

"This is not being controlled, it's not being contained," ABC News Senior Foreign Correspondent Ian Pannell says on "Start Here" today. "In fact the opposite, it's getting worse."

3. Trump challenger

Joe Walsh, a conservative radio host and former Republican congressman, has launched a primary challenge against the president.

Speaking exclusively with ABC News Chief Anchor George Stephanopoulos on ABC's "This Week," Walsh argued conservatives should have an alternative to Trump, calling him "unfit" and "a child."

The one-term congressman's campaign faces an uphill climb against Trump's overwhelmingly high approval rating among Republicans, but ABC News' Rachel Scott says Walsh's run could encourage other primary challengers, "If someone like Joe Walsh starts getting pick-up in a key primary state like New Hampshire, maybe others will think they have a chance too."

In the meantime, the Trump campaign's communications director is dismissing Walsh's bid, telling ABC News: "Whatever."

4. Landmark verdict

An Oklahoma judge is set to issue a landmark ruling today over claims that Johnson & Johnson fueled the state's opioid crisis.

In a $17 billion lawsuit, Oklahoma Attorney General Mike Hunter has accused the drugmaker of using deceptive marketing to downplay the risks of opioids. Johnson & Johnson, which produced the Duragesic and Nucynta painkillers under its Janssen Pharmaceuticals subsidiary, has denied any mismarketing of its painkillers or wrongdoing.

The verdict could open the door for similar opioid cases if the judge rules in favor of the state, according to ABC News' Aaron Katersky, but if Johnson & Johnson prevails, he says, "It could be much harder to hold any one company liable for an epidemic that states believe the company should be on the hook for."

"Start Here," ABC News' flagship podcast, offers a straightforward look at the day's top stories in 20 minutes. Listen for free every weekday on Apple Podcasts, Google Podcasts, iHeartRadio, Spotify, Stitcher, TuneIn or the ABC News app. Follow @StartHereABC on Twitter, Facebook and Instagram for exclusive content and show updates.

Elsewhere:

'I thought he was going to kill me': An African American homeowner says he endured the "most humiliating experience of my life" when white police officers answered a false burglar alarm at his North Carolina home and ended up placing him in handcuffs at gunpoint and walking him to a police car in just his underwear as his neighbors watched.

'Yo Uzi, can you pay for my college tuition?': Rapper Lil Uzi Vert has offered to donate $90,000 for a Philadelphia college student's tuition, and there's video evidence to prove it.

'Get out of my face': An Atlanta attorney has been charged with murder after he fatally rammed his Mercedes sedan into a real estate investor, according to authorities.

'We will come back and kill you': A video surfaced on social media of two transgender women being forcibly and violently removed from the venue by bar staff and security after allegedly being the target of a hate crime by other patrons.

From our friends at FiveThirtyEight:

'Mentally worn down': Even in a sport where early retirements are all the rage in recent seasons, Andrew Luck's sudden retirement has shocked the NFL world.

Doff your cap:

Comedian Dave Chappelle is using his fame to help the community in Dayton, Ohio, recover after a shooter in its popular Oregon District killed nine people and injured dozens more on Aug. 4.

Chappelle will be hosting a free benefit concert Sunday afternoon to benefit the victims and survivors of the shooting, according to the Facebook page for the event, titled "Gem City Shine." The comedian grew up in Yellow Springs, Ohio, about 20 miles east of Dayton.