Cesar Sayoc's case fueled the debate about extremism in the Trump era

A supporter of President Donald Trump was sentenced to 20 years in prison on Monday for mailing crude bombs to prominent Democrats including ex-president Barack Obama and former presidential nominee Hillary Clinton.

Cesar Sayoc, a one-time pizza delivery man who lived in a white truck plastered with pro-Trump and anti-Democrat stickers, broke down and wept as the sentence was handed down in a New York court.

His case fueled the debate about extremism in the Trump era, which intensified at the weekend following two shootings that left 31 dead and dozens wounded in Texas and Ohio.

"The nature and circumstances of the crimes are by any nature horrendous," said District Judge Jed Rakoff as he delivered the sentence.

Sayoc, a one-time strip club DJ and pizza delivery man, pleaded guilty in March to 65 charges relating to 16 package bombs he sent from a Florida post office to leading Democrats and the Manhattan offices of CNN.

The 57-year-old admitted making the homemade devices from materials including plastic piping, a digital alarm clock with electric wiring attached, fireworks and glass fragments.

Besides Obama and Clinton, those targeted included billionaire George Soros, former president Bill Clinton, former vice president Joe Biden, and actor Robert De Niro.

Several Democratic lawmakers, including 2020 presidential hopefuls Cory Booker and Kamala Harris, were also targeted.

None of the packages exploded and most did not come anywhere near their intended recipients but they sparked a two-week panic and heightened political tensions in the lead-up to the US midterm elections in November 2018.

Critics say Trump's anti-immigrant rhetoric helps fuel white nationalist thinking that engenders violence. On Monday Trump said the US "must condemn racism, bigotry, and white supremacy."

Estranged from his family and in financial distress, Sayoc discovered a passion for Trump just as the president's political star was rising.

He shared pro-Trump images on social media and posted articles from ultra-conservative and conspiracy-driven websites such as Infowars and Breitbart. In one post he was seen wearing a "Make America Great Again" hat.

He reportedly ranted to colleagues about Jews as well as blacks and gays.

Trump's inner circle initially attempted to distance the president from Sayoc until filmmaker Michael Moore released footage of the bomber attending a Trump rally, one month after the inauguration.

Prosecutors had called for life imprisonment for Sayoc. His defense said the minimum of a decade behind bars was appropriate, arguing that Sayoc suffered mental health problems and only intended to scare the recipients.

The martial arts practitioner was arrested in Florida in October five days after the first device was discovered in Soros's upstate New York mailbox.

Police found Sayoc's fingerprints and DNA on the packages. He apologized for his actions

Sayoc has a criminal record dating back to 1991, peppered with convictions for theft, fraud, violence and a threat to blow up his electric utility company.