Many in the former Portuguese colony on West Africa's Atlantic coast say the election, only the third since independence in 1975 and the first since the end of a savage 27-year civil war in 2002, was rigged.
Critics of dos Santos and his Popular Movement for the Liberation of Angola, which has held power without any real political opposition for 32 years, say this is stoking growing resentment of a regime run by a cabal of fat-cat politicians, general and well-connected business tycoons as the gap between rich and poor grows ever wider.
The state election commission declared the MPLA took 74 percent of the Aug. 31 vote to retain control of the 220-seat Parliament. That was down from its 2008 showing of 82 percent.
Leonardo Simao, head of an observer mission from the Community of Portuguese Language Countries, reported: "We didn't witness one single case of coercion or intimidation. People voted freely."
But despite the dip in the MPLA vote, critics saw things differently. Elias Isaac of the Open Society Initiative of Southern Africa, observed: "The only surprise for me is that the ruling party didn't get 90 percent."
He claimed many of the 9 million eligible voters shunned the voting.
"The whole system was built to exclude and prevent people from heading to the polls," he said.
More than one-third of Angola's 21 million people live below the poverty line and the disparity between rich and poor is widening, despite the country's oil wealth and the prospect of that swelling on the back of recent deep-water discoveries offshore that are expected to elevate Angola to Africa's top oil producer.
Right now, with a production level of 1.8 million barrels per day, it trails Nigeria, the continent's top producer with an output of 2.5 million bpd.
With the new offshore discoveries in the Kwanza Basin, containing at least 1.5 billion barrels, and Nigeria's oil industry in turmoil, Luanda expects to double output to 3.5 million bpd, on a par with Canada, by 2020.
This could trigger wider unrest.
"Angola is entering a period of political uncertainty and probably greater urban civil unrest," Oxford Analytica forecast in a recent assessment.
"However, despite the country's long history of civil war -- and some analysts' speculation -- a return to armed conflict is highly improbable."
The MPLA's civil war rival, the UNITA movement, has been neutralized since that conflict ended in 2002 and its political-military structure dismantled.
A low-level secessionist insurgency in the oil-rich Cabinda region still splutters but has little impact anymore.
An opposition youth movement, centered in the capital Luanda, has been ruthlessly hammered by security forces and gangs of thugs paid by the intelligence service.
"The president's inner circle has ready access to the financial means to outmaneuver formal political opponents, whether through persuasion of the public or subversion of the electoral process," Oxford Analytica noted.
"It has also shown its preparedness and effectiveness in violent suppression of dissent where it sees this as necessary."
None of this has impeded major international oil companies from seeking to secure production-sharing agreements in Angola's offshore blocks amid West Africa's oil surge.
Britain's BP, Total of France and Norway's Statoil, ConocoPhillips of the United States and Italy's Eni SpA all have obtained exploration rights in the Kwanza and Benguela basins, seen as an extension of Brazil's prolific Santos and Campos zones.
The Financial Times reported that BP has acquired four new blocks covering 7,490 square miles.
"The awards, including a 40 percent stake in a separate block in the Benguela Basin, mean the British group now has interests in nine blocks, accounting for a total acreage of 12,680 square miles," the business daily noted.
Angola's oil wealth, plus its diamond fields, has made it a major economic power in southern Africa, rivaling South Africa.
Pretoria has established close relations with Angola, where the African National Congress maintained guerrilla training camps during the apartheid era in the 1970s and 1980s.
But in the final analysis Angola and South Africa are competing for influence in southern Africa. Angola's burgeoning oil wealth could be the deciding factor.