It doesn't change what the maximum penalty is for that particular crime. What it means is that the judge is to take that factor into consideration when deciding, within the range that's provided by the criminal law up to the maximum sentence already provided, at what level the penalty should be. If it's motivated by hatred, the idea is that the judge would take that into consideration in basically moving the penalty upward from what would normally be the penalty imposed, had the mischief not been committed because of the hate motivation.
That's how it's designed to work. It doesn't bump up the maximum sentence that's provided for the crime.