The Kremlin gained control of all major television channels and their news reports turned into uncritical recitations of Putin's programs, often augmented with admiring footage of him riding horseback, scuba-diving or petting wild animals.
But the protests, sparked by allegations of widespread fraud in December's parliamentary elections, forced notable changes.
Authorities gave permission, however grudgingly, for opposition rallies that attracted vast crowds, upward of 50,000 in Moscow. State television gave them substantial and mostly neutral coverage.
Whether that tolerance will last after the election is unclear. According to the most recent survey by the independent Levada Center polling agency, Putin is on track to win the election with around two-thirds of the vote against four challengers enough to bolster his irritable denunciations of the protesters as a small, coddled minority.
Putin has repeatedly alleged that the protesters are stooges of the United States and Western European countries that want to undermine Russia and he has insulted them, saying for instance that their white ribbon emblems looked like condoms.
In the past week, the rhetoric became even harsher as Putin publicly suggested the opposition was willing to kill one of its own figures in order to stoke outrage against him. That claim came on the heels of state television reports that a plot by Chechen rebels to kill Putin right after the election had been foiled. Some of Putin's election rivals dismissed the report as a campaign trick to boost support for him.
Protests after the election appear certain.
"People in Russia are not going to recognize Putin's victory in the first round," Alexei Navalny, one of the loosely knit opposition's most charismatic figures, declared flatly this week.
Another prominent protest figure, Ilya Ponomarev, a parliament member from the opposition A Just Russia party, said the protesters' mood has become more truculent as authorities consistently brushed off their initial demands for nullifying the results of the December parliament election.
"It has evolved from 'we demand a rerun' to 'go to hell'," he said.
The Interior Ministry is calling in 6,000 police reinforcements to the capital from other regions, the state news agency ITAR-Tass reported Friday.
Whether Sunday's vote is seen as honest is likely to be key; a count without reports of wide violations could deprive protesters of a galvanizing issue.
As the first protests roiled the country, Putin announced an expensive program to place two web cameras in each of the country's 90,000 polling stations, one showing a general view and one focusing on the ballot box. However, their effectiveness is in doubt.
"Cameras cannot capture all the details of the voting process, in particular during counting," the election observation mission of the Organization for Security and Cooperation in Europe noted in a report on election preparations.
Along with the OSCE mission, tens of thousands of Russians have volunteered to be election observers, receiving training for activist groups on how to recognize vote-rigging and record and report violations.
In the December election, observers from the non-governmental group Golos reported being threatened and kicked out of polling stations. Hostility to the group among officials remains; in January, the head of the Federal Security Service in the Komi republic called the group "extremists" inspired from abroad.
"The Russian government has done the right thing by allowing unprecedented public protests and proposing some reforms," Hugh Williamson of the international watchdog Human Rights Watch said in a statement. But "despite the positive developments, the climate for civil society is as hostile as it ever was."
In his past four years as prime minister a sojourn he took because of a constitutional limit of two consecutive presidential terms the steely Putin remained Russia's dominant political figure, overshadowing mild-mannered successor Dmitry Medvedev, who spoke often of reforms but accomplished little.
Putin has promised to appoint Medvedev prime minister if he wins the presidency in order to pursue his reform ideas, but many regard Medvedev as lacking the hard-edge political skills to be an effective reformer.
In addition, appointing him premier could anger the opposition by echoing an earlier humiliation the day in September when Putin and Medvedev told an obedient convention of the ruling United Russia party that Medvedev would step aside from seeking a second term in order to allow Putin to run.
The decision, done without public input and presented as a fait-accompli, was widely seen as cynical and antidemocratic even an analyst close to the Kremlin called it a "filthy deal" and contributed strongly to the growing disillusion with Putin.
Despite that dismay, none of the other candidates have been able to marshal a serious challenge to Putin. The Communist Party candidate, Gennady Zyuganov, gets support of about 15 percent, according to the Levada center survey, which claimed accuracy within 3.4 percentage points. The others nationalist firebrand Vladimir Zhirinovsky, Sergei Mironov of A Just Russia and billionaire Mikhail Prokhorov were in single digits.
Associated Press writer Nataliya Vasilyeva in Moscow contributed to this report.