When Russian President Vladimir Putin was preparing for June's nationwide vote on potentially extending his rule until 2036, he let the veil slip on part of the calculation behind the constitutional change.

"If this doesn't happen, then in about two years — and I know this from personal experience — the normal rhythm of work of many parts of government will be replaced by a search for a possible successor," Putin said in an interview with state TV channel Rossiya. "We must be working, not looking for successors."

The Kremlin won the vote, declaring it a triumph. The constitution now will allow Putin to return to power for another two six-year terms. Independent monitor Golos, however, reported unprecedented vote fraud, and political opponents say the elaborate maneuvering over the ballot has weakened Putin's legitimacy. Public discontent over Putin's rule has begun to spill into the open in Russia's Far East, where tens of thousands have marched in protest recently.