why does the MSM continue to pretend that Rand Paul is a TEA Party voice?
Because the media thinks, or wants us to think, that the Tea Party is the Ron Paul movement grown up.
For the same reason that they wanted Huckabee in 2008 and Santorum in 2012 to represent Social Conservatism.
They made them in satirical caricatures that were easy to ridicule, and beat, rather than the authentic thing.