Dauphin County, Pennsylvania - A man pleaded guilty on Tuesday to attempted murder for firebombing the home of Pennsylvania governor and prominent Democrat Josh Shapiro, and now faces between 25 and 50 years imprisonment under a plea agreement, prosecutors said.

Cody Balmer (38) told police he harbored "hatred" towards Governor Shapiro.

In April, he threw a Molotov cocktail at the Democrat's official residence as Shapiro marked the first night of the Passover holiday with friends and family.

Asked what he would have done had he encountered Shapiro in the residence during the attack, Balmer told investigators he would "have beaten him with his hammer."

"Balmer pleaded guilty to attempted murder of Governor Josh Shapiro, aggravated arson, 22 counts of arson, one for each of the 22 victims within the residence endangered by the arson, burglary, and related offenses," the Dauphin County District Attorney prosecutor's office said in a statement.

"After the defendant's guilty plea to all counts, he received the agreed-upon sentence of not less than 25 years or more than 50 years."

Shapiro, widely viewed as a potential 2028 presidential contender, was inside with his family when the fire broke out in a different part of the Georgian-style mansion in Harrisburg.

No one was hurt, but parts of the residence were badly damaged.

"It's especially hard to know that he tried to murder our family... the hardest part has been to try and explain it to our four children," Shapiro said in an emotional statement after the plea.

"Serving in public office today brings risks. It's a sad state of affairs."

The US has faced a rash of political violence in recent months, with the killing of conservative influencer Charlie Kirk following the targeted killing of a Democratic Minnesota lawmaker and her husband, and the assassination of an insurance executive in broad daylight.

"We need real accountability for acts of political violence," Shapiro said. "Today is real accountability... this is a just outcome."