He sent a copy of the letter to every member of City Council.
Street initially dismissed the question of why voters would trust him to manage the city's $3.5 billion budget when his personal finances have been an absolute wreck for nearly a decade.
Street spent 26 months in federal prison and then a halfway house for not paying taxes on $3 million in income from 2002 to 2004. New Jersey and Philadelphia also claim unpaid taxes.
Street later turned introspectful, saying his troubles were the result of "personal problems and the rigors of entrepreneurship."
He said that makes him keenly aware of the problems city residents and businesses face.
"Michael Nutter doesn't face this because he has lived in a cocoon on a government salary for decades now," Street wrote.
Nutter was a City Council employee and then a Councilman before winning election in 2007.
Nutter yesterday said "everyone is entitled to their opinion" when asked about Street. He added that he was sure voters "will take into consideration a wide variety of factors" like Street's financial troubles in the primary.
A walk with Street yesterday showed he has some support.
Street spent about an hour roaming the hectic intersection of Broad and Erie, greeting people on the sidewalk, in pizza shops, lunch counters and stores as if each new face belonged to a long-lost friend.
Some seemed startled and unfamiliar with the amiable man reaching for their hands to shake. Others shouted his name and offered encouragement.
"We're going to get Nutter out of there," Charmaine Palmer told Street as she worked the grill at the Coffeeland lunch counter.
Next door, at Black & Noble bookstore, Mike Johnson was pushing his wares outside using a karaoke machine when he spotted Street approaching.
Street is basing his campaign on reaching out to people he calls the "Don't Counts," including the poor and formerly incarcerated.
Black & Noble's front wall was painted with a large sign proclaiming: "We ship to prison."
"The next mayor of Philadelphia, Mr. Milton Street, is in the building, y'all," Johnson exclaimed into his microphone. "He ain't like Nutter."