Incumbent Russian President Dmitry Medvedev broke nearly a week's silence Friday on why he meekly stepped aside and allowed Vladimir Putin to take the ruling United Russia party's presidential nomination – which virtually guarantees Mr. Putin's victory in elections next March.

His explanation: Putin is more popular.

"Prime Minister Putin is definitely the most authoritative politician in our country and his rating is somewhat higher [than mine]," Mr. Medvedev said in remarks broadcast on all major Russian TV networks and published in full on the Kremlin's official website.

At a convention of United Russia last weekend, Medvedev ended years of speculation by nominating Putin to be the party's standard bearer. Since the Kremlin-backed United Russia traditionally deploys vast resources to ensure its desired result, and any serious opponents are winnowed from the ballot well in advance, there seems little doubt that former President Putin is set to return for one, and probably two, six-year terms that may see him dominating the Kremlin until 2024.

In his acceptance speech, Putin stunned even some hard-boiled Russia observers by admitting that he and Medvedev had cooked up this plan "several years ago," apparently as a way of keeping Putin's chair warm while he sidestepped the Russian Constitution's ban on any single person serving more than two consecutive terms as president.

Medvedev, in his remarks Friday, seemed at pains to explain to his supporters – including many liberal-minded people who had taken his declarations about the need to reform Russia's top-heavy, heavily centralized, and corruption-ridden political system at face value – by suggesting he might have fought for the nomination if he'd been more popular.

"I was not deceiving anyone when I said the things I did, because life can indeed make sudden changes to any plans and scenarios," he said. "At the same time, yes, we did already have an agreement between us."

Unlike the US, where the two major political parties hold exhaustive primaries for their presidential candidates, and inner-party primary challenges to an incumbent president are not unheard of, the members of United Russia had no say whatsoever in the decision Putin and Medvedev sprung on them last weekend.

Medvedev, who speaks English, enjoys Western rock music, and forged a good working relationship with President Barack Obama during his four years in the Kremlin, appeared somewhat hazy on the finer points of the US political fray.

"I read various political analyses saying things like, 'What, they are not going to both take the political stage and battle it out to the bitter end, stage a competition between themselves? How can this be?'" he said. "But you don’t see this kind of thing in any country. People who are part of the same political force choose together who to put forward and how to proceed.... Can you imagine a situation where Barack Obama, say, starts competing against Hillary Clinton? They both sought nomination as their party’s candidate for president. This kind of rivalry just wouldn’t be possible. They represent the same party, the Democratic Party, and their decisions were based on which candidate they thought would bring the best result," he said.

When Medvedev became president in 2008, he appointed Putin as prime minister. Putin hinted at the United Russia convention that he will return the favor to Medvedev when he assumes office.

Medvedev, whose pledges of reform during nearly four years in the Kremlin led to few results, said that he will strive to change the political system if he becomes prime minister.

"The government should be modernized," he said. "So if it so happens that the Russian people entrust United Russia with forming the government and if our people vote for our presidential candidate, and this government is formed by me, then it will be an absolutely new government consisting of new people."

Alexei Makarkin, deputy director of the Center for Political Technologies, an independent Moscow think tank, says that Medvedev's credibility has taken a serious hit in the past week, one from which he is unlikely to recover.

"Medvedev understands that he has disillusioned a lot of people who wished for a different development of events," Mr. Makarkin says. "And he knows he can not position himself as a lame duck. So he's in a very difficult position....

"Of course, there is some part of the electorate who will just say that authorities are authorities, we support them, and for those people Medvedev's explanation might be acceptable," he says.

"But for more demanding and skeptical voters it will not work at all.... [What they see] is that, compared to leading democratic countries, in Russia elections are merely a means to legalize decisions that have already been taken," at the top.