Obama's been talking about how great a mover of ideas Reagan was. Although I don't agree with much of what Reagan stood for, Obama's right as rain: Reagan came at a time when the country needed and wanted someone like him, and he offered a vision to America, not just bullet points.
If you look at a map of how Reagan swept across America in 1980 and 1984, you'll see this visually: essentially, there were no blue states.
Viewed in the context of the times, and without the advantage of historical hindsight, this speech is rousing. It just is.
And damn, they had some hair back then, huh? "Get the Vitalis, get the Vitalis!"