A woman who allegedly mailed fake toxins to Sen. Susan Collins is headed to trial.

Suzanne Muscara, 37, pleaded not guilty to the charge of mailing a threatening communication on Thursday.

She was allegedly enraged by Collins' support for Supreme Court nominee Brett Kavanaugh, who was confirmed 50-48 after he was accused of sexual misconduct by a high school and college classmate.

Muscara was arrested by the FBI April 5 after a partial fingerprint was found on one of two letters that she allegedly mailed to the Republican senator's home in Bangor, Maine, after Kavanaugh's Oct. 6 confirmation.

One letter, opened on Oct. 15 by Collins' husband, claimed to be coated in "ricin residue," and the second arriving two days later purported to contain anthrax. Authorities found only white starch powder.

According to court documents, one letter told Collins's husband: "Good Luck to you and Susan in the next life ... Your wife has betrayed the people of Maine along with the American people and this will be her downfall.’"

Muscara's trial is set for June 4. If found guilty, she faces up to 10 years in prison.

The developments in Muscara's prosecution were reported Friday evening by the Portland Press Herald. She entered her plea on Thursday.

Despite a fierce public debate and advocacy campaigns, just one Republican senator present for the vote did not back Kavanaugh. Sen. Lisa Murkowski voted present.