Six men planned to capture Michigan Governor Gretchen Whitmer at a holiday home and put her on "trial". One suspect allegedly called her a "tyrant". The suspects reportedly used Facebook to plan the alleged kidnapping.
Seven other men belonged to a paramilitary group. They allegedly wanted to invade the state seat of government and seek "civil war".
Michigan was the scene of anti-lockdown protests, which included some gun-toting men in military-style gear, earlier this year. Other such protests occurred in Wisconsin and Arizona.
President Donald Trump, who has sparred with Democrat Whitmer, tweeted in mid-April for his supporters to "liberate Michigan" so businesses could reopen.
Armed protesters on April 30 entered the Michigan statehouse. On May 2, Trump tweeted that such protesters "are very good people". Two of those arrested last week reportedly took part in that protest.
Heavily armed militias have roamed US streets near protesters this year, as though it is normal behaviour. In August, an armed teenager was charged in the shooting and killing of two protesters and the injuring of a third in Kenosha, Wisconsin.
People spouting violent rhetoric and conspiracy theories can easily connect online and increasingly on mainstream social media platforms.
US security agencies consider domestic terrorism by white supremacists and other extremists as the country's top threat. A Department of Homeland Security assessment said this month that "2019 was the most lethal year for extremism in the US since the Oklahoma City bombing in 1995".
The presence of Trump in the White House and the challenges of 2020 have made far-right groups more visible. Experts say fears surrounding the coronavirus and its impact on life have stirred more interest in extremism.
A booming economy in recent years has not hidden systemic problems. The coronavirus outbreak and restrictions, mass unemployment, foodbank lines, protests over police brutality, and political dysfunction have piled on the pressure.
People attracted to far-right groups in the US have previously tended to be against the federal government. But anger now seems to be directed at state officials.
"This is largely due to the fact that Donald Trump, who the militia movement supports, is at the head of the federal government," said Mark Pitcavage, of the Anti-Defamation League's Centre on Extremism.
Whitmer noted that in the first presidential debate Trump told a far-right group to "stand back and stand by". She said: "Hate groups heard [it] as a rallying cry, as a call to action". Trump tweeted that he does not tolerate extreme violence.
During the campaign, Trump has hammered the claim that the US is under threat from left-wing anarchists as part of a "law and order" stance. He has also pushed the idea that the election would be illegitimate if he loses.
"Donald Trump has succeeded in being at once the head of government and the head of anti-government," said Lawrence Rosenthal, of the University of California, Berkeley, who studies far-right groups.
It all adds up to an uncertain time ahead.
