What's Happening in Bolivia and Venezuela?

The MSM informed me that Evo Morales and Hugo Chavez, Venezuela's president and staunch Morales ally, ordered the US ambassadors expelled from their countries last week, but I didn't hear any explanation of why this had happened. Did you? Al Jazeera summarizes;

Some provinces oppose Morales' push to empower the indigenous majority [AFP] Morales has offered no detailed evidence of Philip Goldberg's alleged conspiracy with the opposition, but has accused Goldberg of egging on anti-Morales forces through meetings with governors who have publicly called for the president to be removed.

But Goldberg denied the charge and called the decision to expel him a big mistake on Sunday in his first public comments on the matter.

"I would like to say that all the accusations made against me, against the embassy and against my nation are completely false and unjustified," he told reporters in La Paz as he prepared to leave.

The gravest challenge to Morales' nearly three years as Bolivia's first indigenous president stems from his struggle with the four eastern lowland provinces where the country's natural gas riches are concentrated and where his government has in effect lost control.

The provinces are seeking greater autonomy from Morales' leftist government and are insisting he cancel a December 7 referendum on a new constitution that would help him centralise power, run for a second consecutive term and transfer fallow terrain to landless peasants.

Morales says the new charter is needed to empower Bolivia's indigenous majority.

and venezuelanalysis.com elaborates in-depth - Magisterial Counter-Attack of the new Latin-American Political Class in Venezuela and Bolivia