Video: the Republican speeches | The bloggers' verdict

Since this almost uniquely unpredictable US presidential primary contest got under way a month ago, everyone at least thought they could agree on one thing. The Republican race, a multi-sided struggle between candidates who represented the many fissiparous strands of conservative opinion, would take months to resolve. No candidate was likely to emerge as the clear frontrunner perhaps until the very end of the primary process in the late spring. For the first time in decades the race might even have to go all the way to the party’s nominating convention in Minneapolis in September.

That now looks like yet another short-lived piece of political wisdom in this wisdom-mocking primary campaign.

John McCain’s victory in Florida on Tuesday has positioned him suddenly as the party’s almost unassailable frontrunner. It is quite likely now that the Super Tuesday contest next week, when 22 states will hold primary votes, will produce enough delegates for Mr McCain to have wrapped up the nomination, at least in political practice if not in numerical certainty. While it is now the Democrats who look to be in for the long haul in the contest between Hillary Clinton and Barack Obama, the Republicans are very likely to know the identity of their nominee in less than a week.

Why has this most unpredictable race suddenly got predictable?

First, Mr McCain is the only candidate to have established real momentum. He has now won three of the first five seriously contested primaries – including, for the first time in this race, two in succession. He won the last primary in South Carolina ten days ago and has now followed up with Florida. Mitt Romney, the former governor of Massachusetts and Mike Huckabee, the former governor of Arkansas have each won one.

Because of the rules of the Republican primary it was always likely that if a candidate gained serious traction, he would accelerate to the nomination.

To win the party’s nomination a candidate needs to gain a majority of the 2,000 or so delegates elected by the various states in the primaries and caucuses around the country. In the Republican race a high proportion of these are awarded on a winner-take-all basis.

In a multi-sided contest that means a candidate could take all that state’s delegates with little more than 30 per cent of the vote – which is exactly what Mr McCain did in Florida.

Next week’s Super Tuesday primaries are even more promising for Mr McCain. In some of the big states - New York, for example and Arizona - the state-wide winner of the popular vote takes all that state’s delegates. In others, such as California, the delegates are awarded to the winner of the popular vote in each of the state’s congressional districts. Mr McCain currently has sizeable opinion poll leads in many of those states – meaning he should pick up all the delegates in many of those states and a sizeable majority in others. At a conservative estimate, Mr McCain should emerge from next Tuesday with 600 or 700 delegates – just a few hundred short of the number needed to win the nomination.

Rudolph Giuliani’s decision to drop out on Wednesday and endorse Mr McCain will only strengthen the Arizona senator on Super Tuesday. Mr Giuliani was the only serious challenger in several states such as New York and New Jersey. Now that he is gone, those states should be in the bag.

Conversely, also good news for Mr McCain is Mr Huckabee’s decision to carry on to Super Tuesday, despite a fourth place showing in Florida. While Mr McCain and Mr Giuliani were competing for similar voters – somewhat unorthodox, moderate Republicans and independents, Mr Huckabee has been in a struggle for conservative votes with Mr Romney. If, as seems likely, Mr Huckabee can take conservative votes in southern Super Tuesday states such as Georgia and Tennessee, he will further limit the upside potential for Mr Romney, the only remaining plausible alternative to Mr McCain.

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