He said he stood again because he was asked to by people in the ward.
Disability Cornwall said it was “shocked beyond words” and that it was a “sad day for Cornwall”.
The announcement of Mr Brewer’s election was greeted by a mixture of boos and cheers.
He said he had decided to stand again because he was asked to by people in the ward and “all over the county”.
“I have apologised, the people in Wadebridge wanted me to stand and I’m proud to stand for them.
“People said with their votes they knew I didn’t mean that. I resigned because of unbearable media pressure.
“This incident caused outrage….people were truly shocked and saddened by it”
Disability Cornwall “The people of Wadebridge put me back. They know me.”
Mr Brewer said the comments, made to a Disability Cornwall member at a stall at County Hall in Truro in 2011, were only to “provoke debate”.
He said disabled children should be put down because they cost the authority too much money.
The comments came to light following a report by the council’s standards committee after the charity made a formal complaint.
Mr Brewer faced strong criticism and he apologised to the charity, resigned as a councillor and said it was unlikely he would be a candidate in the May elections.
When submitting his candidacy, Mr Brewer said he was re-standing because he had a “good record” of service as a district, county and Cornwall councillor stretching back more than a quarter of a century.
Disability Cornwall chairman Steve Paget said he was “staggered” and “appalled” at the election result.
He said: “I’m just confused that anyone who advocated putting disabled children down in any context could be re-elected as a public figure in Cornwall.”
In a statement, the organisation said many members were “deeply saddened to hear this, and worry what this could mean for us all, with such discriminatory views held by the ‘leaders’ of our county”.
It said: “This incident caused outrage when it was featured throughout the press in the UK and beyond, because, like us, people were truly shocked and saddened by it.
“Truly, a sad day for Cornwall.”