Senate President Thomas V. Mike Miller (D-Calvert) called on Gov. Larry Hogan (R) to tone down his rhetoric after the Senate voted to override his veto of expanded voting rights for felons. (Nikki Kahn/THE WASHINGTON POST)

Maryland Gov. Larry Hogan’s pointed attacks on Democrats who overturned his veto of expanded voting rights for felons appear to have tapped into a current of anger among some state residents, who are sending hate mail and making threatening phone calls to lawmakers who voted for the override.

Senate President Thomas V. Mike Miller Jr. (D-Calvert) read excerpts of letters his office has received since the Senate voted last week on the felon voting rights bill, which will allow felons to vote while they are on probation or parole.

“You need to check yourself, you moron,” one letter said. “You are only selfish fools.”

At least one senator who voted for the override said his office received a call from a man who said he hoped that the senator’s wife and daughter would be raped and murdered.

Miller called on Hogan (R) to tone down his rhetoric, which included labeling those who backed the override as a “radical minority” and speculating that some lawmakers would lose their seats over the issue.

“This is not Washington,” Miller said. “This is Annapolis.”

The governor took to Facebook to urge constituents to contact their senators and express outrage after the override, which passed 29 to 18, without a single vote to spare.

“This is the worst vitriol I have ever experienced in my 34 years in the legislature,” said Sen. John C. Astle (D-Anne Arundel), whose office staff received the phone call about his wife. “It’s just unbelievable.”

Doug Mayer, a spokesman for Hogan, called Miller’s characterization of the governor’s Facebook posts “beyond outrageous and over the line. . . . If these senators don’t want their constituents to be mad at them, then they should stop voting in favor of things that they despise.”

Sen. Jamie B. Raskin (D-Montgomery) likened the response to some of what he experienced during debates in 2013 over abolishing the death penalty and strengthening gun laws.

This time, Raskin said, much of the “fury” seems to be from Republicans who think that Democratic lawmakers “went out to find new voters.” Most of the 44,400 people affected by the override are from the overwhelmingly Democratic city of Baltimore, advocates say.

“There’s a suggestion of a political power grab,” Raskin said. “Emotions are high during election seasons. Things seem to be inflamed by this vote.”

With the override, Maryland joined the District and 13 states, including Massachusetts, Ohio and Pennsylvania, that permit people to vote as soon as they are released from prison, according to the Sentencing Project.

Eighteen states, including New Jersey, North Carolina and Texas, restrict voting rights until after a felon completes parole and probation. Twelve others, including Florida, have stronger restrictions, such as waiting periods after a sentence is completed.

Jane Henderson, executive director of Communities United, a Baltimore-based group that pushed for the expansion of voting rights, said the bill was about allowing more people to participate in the democratic process.

She disagreed with Hogan’s assertion that is it opposed by most Marylanders.

“Larry Hogan was elected in a very-low-turnout election,” Henderson said. “He must think about his election [when] he thinks about expanding the electorate.”

Miller said that the continued partisan attacks could hurt the governor’s repeated calls for bipartisanship. He then offered his own warning to Hogan.

“We need to continue to avoid the pin­pricks to avoid the cannon shot,” Miller said, noting that Hogan needs support from the legislature to advance his agenda. “We have to continue to work together for three years.”