Organizers from two groups decided last week to hold a demonstration and vigil Sunday near City Hall to urge presidential electors to vote their conscience and withhold support from President-elect Donald Trump.

And they said Saturday that news that the CIA had concluded that individuals tied to the Russian government had hacked emails of the Democratic National Committee to help elect Trump only bolsters their argument that he is unfit for the office.

"This is the reason the Electoral College was created," Lital Levy, a South Philadelphia resident and Princeton professor, said. "They have a civic duty to prevent tyranny."

The Support the Electors Unity Vigil is scheduled from 3 to 6 p.m. at Thomas Paine Plaza, 1401 John F. Kennedy Blvd.

"I am doing this as an ordinary, concerned citizen," said Levy, who teaches comparative literature at Princeton. "I'm really concerned about this process and the fate of our nation."

The event is being cosponsored by the Hamilton Electors and a grassroots organization called Protect Democracy - Protest Unfit President Elect.

The nonpartisan unity vigil will urge the 20-member Pennsylvania Electoral College to vote for a candidate other than Trump when it convenes in Harrisburg on Dec. 19.

Writing in The Federalist Papers, Alexander Hamilton said that the purpose of the Electoral College was to make sure the person elected president was qualified, was not a demagogue, and was not under foreign influence.

A group of self-described Hamilton Electors is working to inspire others to join them and vote for a candidate they believe to be more qualified than Trump.

"It doesn't have to be Hillary Clinton," Levy said.

She said Sunday's event will include placards, speakers, and participants holding candles after dusk. She said the event would begin at 3 p.m. so it would be convenient for families.

Demonstrators are asked to wear purple to show that Red and Blue must come together to ensure a more responsible candidate becomes president.

martha.woodall@phillynews.com215-854-2789 @marwooda