Donald Trump on Sunday used a speech in key swing state Pennsylvania to urge a “violent” police crackdown on crime in the United States, while his White House rival Kamala Harris emphasized the need for immigration reform at a rally in Nevada.

Pennsylvania is considered the most important of the seven toss-up states that will likely decide the 5 November presidential election, but Nevada is also one of the key battlegrounds.

The Republican former president and current candidate, who held a similar rally in swing state Wisconsin on Saturday, reprised his dark, racially charged message about an America crumbling under “invasion” by violent migrants and other criminals.

Recounting isolated — but widely publicized — incidents of thieves staging brazen daylight robberies of shops in major cities, Trump got a loud cheer when he said police should become “extraordinarily rough.”

Criminals, he said, “have to be taught” and this could be done “if you had one really violent day.”

“One rough hour — and I mean real rough — the word would get out and it would end immediately,” Trump said.

“The police aren’t allowed to do their job” because “the liberal left won’t let them.”

Harris, the vice president and Democratic candidate, addressed the “serious problems” of border security at a rally in Las Vegas later in the day, where she reeled off her usual stump speech, emphasizing the economy, health care and the need for immigration reform.

“As president, I will double the resources for the Department of Justice to go after the transnational cartels,” Harris said.