The New York Times/Siena College poll found Democratic presidential nominee Joe Biden is ahead in the key battlegrounds of Pennsylvania, Florida, Arizona and Wisconsin.
The Supreme Court ruled Monday that Wisconsin mail-in ballots received after Election Day will not be counted.
"These criminals exhibited a level of familiarity with state party operations at the end of the campaign to commit this crime," Republican Party of Wisconsin Director Andrew Hitt said in a statement given to Newsweek.
North Dakota reported the highest number of deaths per capita in the last seven days, according to the U.S. Centers for Disease Control and Prevention (CDC).
Polls suggest unrest in Wisconsin did not help President Trump win over more voters in the crucial state.
A pair of surveys released by The Washington Post and ABC News on Wednesday found Biden up by 7 points in Michigan and 17 points in Wisconsin among likely voters.
Biden only has a 12 percent chance of defeating Trump if the popular vote is very close, a recent study of the Electoral College finds.
"So does it help the president to continue to dismiss—to dismiss this virus and say that we're rounding a corner?" Sandra Smith asked.
Events kick off with Trump set to speak at 2 p.m. Central Time in Lansing, Michigan, at the Avflight building near the Capital Region International Airport.
In the October 20-26 Reuters/Ipsos poll, 53 percent of respondents said they'd vote for Biden, compared to 44 percent for Trump.
Massachusetts senator criticized the Supreme Court's rejection to extend deadline for counting mail-in ballots in the battleground state.
"As the COVID pandemic rages," Justice Elena Kagan wrote in her dissent, "the Court has failed to adequately protect the Nation's voters."
The number of coronavirus patients in hospital has been rising in several states, including Texas, Utah and Wisconsin.
While the Democratic nominee has gained 3 percentage points since September, the president lost 2 points.
Joe Biden appears to be favored over Donald Trump in Arizona, Florida, Michigan, Pennsylvania, North Carolina and Wisconsin—although the margin is close in some of these battleground states.
"Why doesn't the president follow his administration's own guidelines at his rallies?" Fox News Sunday host Chris Wallace asked Jason Miller.
Nine out of 10 Biden supporters in Wisconsin said that the coronavirus outbreak is a reason they would elect him.
"One, President Trump's rallies pack people close together," said a Wisconsin doctor. "Two, his rallies give him a bullhorn to spread misinformation..."
A day before Trump's visit to Wisconsin, a local Republican county executive revealed that he'd tested positive for COVID-19.
Sgt. Michael Sturek, 39, with the Mauston Police Department in Wisconsin, is facing charges including felony second-degree recklessly endangering safety.
Only 39 percent of Michigan residents plan to vote for Trump, the new poll shows.
Several states in the Midwest of the country, including North and South Dakota, have reported the highest number of infections per capita in the last week.
Lynn BeBeau and her husband Mike turned detective to trace the origins of the little wooden boat which bore an inscription.
Prosecutors say there is no evidence that the rifle used in the shootings was ever possessed by the 17-year-old in Illinois.
Trump won each of the four states against Hillary Clinton in 2016, but a new poll shows Biden with single-digit leads in each.
The worst-hit metro areas were reported to be in Wisconsin, Texas, Idaho, Iowa, North and South Dakota, South Carolina and Montana, according to a new report.
President Donald Trump has been accused of inciting armed groups to attend polling places in November.
Mayor Dennis McBride said the decision about Officer Joseph Mensah's continued employment was "not in the hands" of his office.
A recent poll showed the former vice president had a higher level of public figure approval than the president.