By the time you read this newspaper, polling will be well under way across the world's biggest country, and Vladimir Putin should be well on his way to a fourth term as Russia's president.

The only unknown in this election is whether he will win the 50% of the vote required to give him an outright victory today, or whether a (for him, humiliating) run-off will be needed. The last opinion polls suggest he will sail home in the first round.

Mystifying and depressing though it may be to many Western observers, Putin can still dig into a deep vein of support, principally among Russia's less well-off and less well-educated; and those who believe Russia needs a strongman leader to hold the country together and stand up to the West.

Not that Putin and his election team – effectively the entire state apparatus – have taken any chances. No string was left unpulled in a campaign that didn't even pretend to be free and fair. The state TV channels broadcast documentaries portraying Putin as the man who "saved Russia" from the chaos of Boris Yeltsin's rule and from the alleged meddling hands of the West.

The Putin team also came up with a few unusual stunts. Last week it was announced that a plot to assassinate Putin had been foiled – they also foiled an assassination plot just before the last presidential election.

Then Putin warned of murky deeds being plotted by the opposition for after the election: they might provoke some kind of sabotage, a death even, during street protests, which would be blamed on the authorities.

For the record, there are four other candidates. From the far right to far left, they are:

l Vladimir Zhirinovsky, a nationalist buffoon who spouts endless populist promises that he knows he will never need to implement;

l Mikhail Prokhorov, a "pro-business" billionaire and owner of the New Jersey Nets basketball team, whose only memorable campaign move was to sing/rap a song, as though campaigning for president was just a bit of a lark.

l Sergei Mironov, a lacklustre centre-left politician who until recently was trusted to run the upper house of parliament.

l Veteran communist party leader, Gennady Zyuganov, who – as President Dmitry Medvedev admitted at a recent meeting with opposition leaders – actually won the 1996 presidential election, which was fiddled in order to keep a sick, alcoholic Yeltsin in power.

Just as certain as Putin's victory is that protests will follow. Huge numbers of Russians simply do not trust the authorities to run a fair election. Voting for the Russian parliament last December was marred by widespread ballot-stuffing and falsification.

In response to popular anger, Putin ordered CCTV cameras to be installed in every polling station for today's vote. But much of the fraud takes place during the counting of votes and filling in of results sheets, rather than during the actual voting.

So Putin will be declared the winner tonight. And the opposition has already applied for permission to hold a protest rally next week.

In the last months, Russian politics has suddenly emerged from years of hibernation. Hundreds of thousands of people are now willing to demand political change. The big question for Russia is how Putin will deal with this.

One option is to make concessions – one or two have already been wrung out of the Kremlin. In future, it will be easier to register new political parties, and regional governors may be elected rather than appointed by the Kremlin.

But the opposition wants more, including a re-run of the parliamentary election.

The whole scenario is reminiscent of what happened in Georgia in 2003 and Ukraine in 2004, when rigged elections caused mass protests and ended with the overthrow of the "old regime" in favour of Western-oriented politicians. Putin is known to have urged President Leonid Kuchma of Ukraine in 2004 to use force to squash the Orange Revolution protests. Would he do that in Russia? That would be his second option.

We heard something of the real Putin a week ago, at a mass rally in the Luzhniki sports stadium in Moscow, filled to the brim with his supporters. In his usual pugnacious style, he called on Russians not to give in to foreign powers who wanted to "impose their will" on Russia, exhorting the crowd to roar "Da! Da!" to his question "Do you love Russia?" equating Russia's future with his own future as president.

But for all his warlike rhetoric, he looked small and somehow vulnerable on that huge empty platform in the middle of the sports arena. He "looked terribly lonely", according to one commentator, Konstantin Eggert.

Eggert said: "Putin is searching for a new formula to retain power. It may seem paradoxical, but for the first time maybe in his career he's been forced to behave not like some omniscient chieftain who can't be contradicted, but as a public politician who actually needs to win the people's support."

Although things will look superficially the same in Russia after today's election, everyone – including Putin – knows that the political landscape has changed. It shifted last September, when Putin and Medvedev announced that they would swap roles after this election. The chutzpah of that announcement, followed by the rigging of the December parliamentary election, stirred Russia's middle classes into action.

Observers expect Putin to devote the next six years to finding a successor – one who will not only preserve the "Putin system" but also guarantee him, when he finally steps down, immunity from prosecution.

Russia: Putin will be re-elected president ... but the

country is changing politically. By Angus Roxburgh