WASHINGTON — Republicans opened the third night of their convention with an aggressive defense of law enforcement, as the nation faced renewed tensions following the police shooting of a Black man in Wisconsin that has sparked three nights of protests in a state that could decide the fall election.

The opening speakers seized on the national reckoning over racial injustice to argue that Democratic leaders are allowing lawlessness to prevail in cities from coast to coast.

"From Seattle and Portland to Washington and New York, Democrat-run cities across this country are being overrun by violent mobs," declared South Dakota Gov Kristi Noem, though the protests of racial injustice this summer have been largely peaceful in most locations. "People that can afford to flee have fled. But the people that can't -- good, hard-working Americans --are left to fend for themselves."

Meanwhile, the steady image Republicans are aiming to portray of President Donald Trump was running into a turbulent reality. The police shooting of Jacob Blake, a 29-year-old Black man, in Kenosha, Wisconsin, has sparked a new round of protests. A potentially catastrophic hurricane was bearing down on the Gulf Coast, wildfires have ravaged huge areas of California and the still-raging coronavirus pandemic is killing more than 1,000 Americans a day.

The historic convergence of health, economic, environmental and social emergencies is only increasing the pressure on Trump, as he looks to reshape the contours of his lagging campaign against former Vice President Joe Biden with Election Day just 10 weeks off and early voting beginning much sooner.

The GOP's convention response to those growing challenges has been uneven. While Trump has issued tweets about the hurricane, few convention speakers addressed it or the wildfires. The convention lineup has included speakers who have been at odds with the Black Lives Matter movement, including a St. Louis couple who brandished guns and the Kentucky attorney general who has not yet filed charges in the death of a woman killed by police.

Adding still another controversial element, late Wednesday the NBA postponed three playoff games after the Milwaukee Bucks refused to take the court for their game following the shooting of Blake. The WNBA and Milwaukee Brewers quickly followed suit with their Wednesday games.

That was a few hours before Vice President Mike Pence was to speak from Baltimore's Fort McHenry, where an 1814 battle inspired the National Anthem. Trump has strongly criticized athletes who kneel rather than stand during the anthem in protest of racial injustice.

Adding to the sense of convention uncertainty, another speaker was abruptly pulled from the lineup. The Trump campaign confirmed that Robert Unanue, the president and CEO of Goya Foods, would not be speaking Wednesday night, citing a "logistical problem." Unanue's appearance at the White House earlier this month and his praise of Trump sparked a boycott movement of his company's products.

Organizers on Tuesday had pulled another featured speaker, "Angel Mom" Mary Ann Mendoza after she directed her Twitter followers to a series of anti-Semitic, conspiratorial messages hours before her pre-recorded segment was to air.

Wednesday night's lineup was expected to include Clarence Henderson, who participated in the 1960 Greensboro, North Carolina, Woolworth lunch counter sit-ins for what Trump's team said would be a discussion of "peaceful protest" and the president's record of trying to help Black Americans.

"These achievements demonstrate that Donald Trump truly cares about black lives," Henderson was to say. "His policies show his heart. He has done more for black Americans in four years than Joe Biden has done in 50."

Convention speakers were also reinforcing Trump's law-and-order message, warning that electing Biden would lead to violence in American cities spilling into the suburbs, a message with racist undertones. Trump on Wednesday tweeted about sending federal agents to Kenosha to help quell unrest, and the Justice Department said it was sending in the FBI and federal marshals.

Trump's campaign believes his aggressive response will help him with suburban women voters who may be concerned by the protests -- though it may only deepen his deficit with Black voters.

Michael McHale, the president of the National Association of Police Organizations, told the convention, "The violence and bloodshed we are seeing in these and other cities isn't happening by chance. It's the direct result of refusing to allow law enforcement to protect our communities. Joe Biden has turned his candidacy over to the far-left, anti-law enforcement radicals."

And Burgess Owens, a former NFL player now running for Congress in Utah, declared, "This November, we stand at a crossroads. Mobs torch our cities while popular members of Congress promote the same socialism my father fought against in World War II."

The program Wednesday was - as the president might say -- low energy, with no major headline speaker beside the vice president and few boldface names. And it lacked some of the production elements that had made previous nights of the convention memorable, including slickly-produced videos and surprise announcements, such as an unexpected presidential pardon and a citizenship ceremony.

While the Democrats' convention last week included musical performances and celebrity guests, Trump's on Wednesday become little more than a series of speeches, delivered one after the next.

The night included remarks from the president's daughter-in-law, Lara Trump, as well as several administration officials including departing Counselor Kellyanne Conway, the manager of Trump's 2016 general election campaign, and press secretary Kayleigh McEnany.

"This is the man I know and the president we need," said Conway, a week before she is to leave the White House. "He picks the toughest fights and tackles the most complex problems. He has stood by me, and he will stand up for you."