The Culture Secretary hit out at Tory leader David Cameron's use of isolated incidents to brand all young people bad.
Mr Cameron was particularly criticised for his suggestion last month that the case of two boys who attacked two other children in Edlington, south Yorkshire should prompt questions over what has gone wrong in society.
Before launching his party's plans to "mend our broken society", he said people should not dismiss such crimes as isolated incidents and forget about them.
Mr Cameron said: "When we think about these terrible crimes, I don't think it's right every time one of these events take place to say that it is just some isolated incident of evil that we should look away from and forget about."
But attempts by Conservatives to use the breakdown of social values for political gain has attracted the wrath of Labour politicians.
Tony Blair faced similar criticism when, as shadow home secretary, he made a speech on the death of toddler Jamie Bulger as a sign of social breakdown under the last Tory government.
Mr Bradshaw, speaking to a group of students, said: "I think there is unfair demonisation of young people.
"It's not fair when people like David Cameron use an isolated example — the terrible case of the children who tortured other children — to claim that Britain is broken, that we are a whole broke society and all young people are bad. That is not the case."
Mr Bradshaw, the Cabinet minister responsible for culture, media and sport, said there needed to be more coverage of the good things young people were doing.
"There are thousands of young people, being sports leaders, community leaders, leaders in music, in culture and making a positive contribution," he said.
"We need more coverage of that and less coverage of the minority of young people who are causing the problems."
Last week Prime Minister Gordon Brown was quizzed by Rebecca Stokes, of the Echo's Teen Team, who said teenagers too often have a "negative image — of yobs and hoodies".
At the Cabinet event held in Devon, Miss Stokes said many young people would like to have more opportunities to make decisions.
Mr Brown said he wanted to create a situation where young people could have a say in the services they use.