La Paz, Bolivia ? President Evo Morales’ party won a majority Sunday in elections for an assembly that will retool Bolivia’s constitution but fell short of the two-thirds needed to push through its leftist agenda, according to unofficial preliminary results.

The results, based on the PAT television network’s report of actual vote tallies at 87 percent of the nation’s polling stations, gave Morales supporters 132 seats in the 255-member assembly. The assembly will take up to a year to rewrite the constitution. Two-thirds of the body must approve the changes, which then must be endorsed in a nationwide referendum.

In a separate ballot question, four of Bolivia’s nine states voted overwhelmingly for greater political and economic autonomy from the central government, according to the unofficial results.

The autonomy issue exacerbated long-standing tensions between the country’s wealthier eastern lowlands and the poorer, less fertile Andean highlands that are Morales’ bastion of support.

The split on autonomy was right along Bolivia’s geographic fault line. Voters in the eastern state of Santa Cruz, Bolivia’s wealthiest and largest, approved autonomy by 78 percent of the vote, the exit polls showed.

Its residents widely resent what they consider Morales’ attempts to siphon money from their region in order to push his efforts to empower the nation’s long-neglected Indian majority and exert greater state control over the economy.