The US election campaign, with a week to go

President Donald Trump was barnstorming in a last-ditch effort to keep Midwest states, while challenger Joe Biden was aiming to flip a Republican bastion as rage over police violence erupted anew.

Here is a look at what's happening in America's campaign on Tuesday, one week before November 3 Election Day:

Trump is down in the polls and has been hitting the road hard. On Tuesday he held rallies in Michigan, Wisconsin and Nebraska.

"I've got to say I'm working my ass off here!" he boomed in Lansing, Michigan, eliciting a huge cheer.

Trump carried all three in 2016 -- Michigan and Wisconsin were key to his shock victory -- but the RealClearPolitics average shows him behind by at least five points in each.

Meanwhile, First Lady Melania made her first campaign appearance in Pennsylvania -- another state Trump won four years ago but where Biden is leading the polls. She praised the president as a "fighter."

Trump's wife was due to visit Erie, Pennsylvania last week, but she opted not to travel, citing a "lingering cough" from her bout of coronavirus.

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Biden campaigned in the once reliably Republican state of Georgia, first in the town of Warm Springs and then a socially distanced drive-in car rally in Atlanta.

In Warm Springs, he branded the White House response to the Covid-19 pandemic a "capitulation" and said Trump had "shrugged, he swaggered and he surrendered."

Polls have Trump running neck and neck with Biden in the Peach State.

Georgia last voted for a Democrat for president nearly 30 years ago -- Bill Clinton in 1992 -- but the Biden campaign has high hopes of flipping the state as the population skews younger and more diverse.

Obama was back stumping for his former vice president in Florida, telling a rally: "We got one week, Orlando. One week. One week until the most important election of our lifetimes."

Biden's running mate Senator Kamala Harris hit Nevada, which went for Hillary Clinton in 2016. There she told reporters she and Biden believe they have to "earn" votes.

Simmering rage over police killings of minorities erupted again late Tuesday, with protests in Philadelphia for the second night running, sparked by an officer's fatal shooting of a Black man.

Local media reported that two officers shot the man on Monday afternoon after he refused to drop a knife as his mother tried to restrain him, though his family questioned why lethal force was needed and said he suffered mental health issues.

His girlfriend was also wounded in the shooting. On Tuesday she challenged the official version of events and said she was filing for compensation.

Months of often-violent protests have rumbled across America this year, as outrage over the repeated killings boiled over.

Late Monday, during a night of sporadic riots and looting in the city with hundreds of protesters, around 30 police officers were injured, including one whose leg was broken when hit by a truck.

The candidates have pledged starkly different responses, with Trump vowing "law and order" crackdowns, while Biden has promised reforms to fight systemic injustices.