The Republican race: A bit of a breakthrough THE race for the Republican presidential nomination has followed a consistent pattern. Every month or so a candidate emerges from the pack to threaten Mitt Romney's lead, only to drop back after a week or two. It used to be a new challenger each time: Michele Bachmann, Herman Cain, Rick Perry and so on. Lately, it has been the same man periodically snapping at Mr Romney's heels before falling behind again: Rick Santorum, a former senator from Pennsylvania. This week Mr Santorum flubbed yet another chance to overtake Mr Romney, by losing the primary in Illinois. That is great news for Mr Romney. After Georgia, Illinois is the biggest prize yet, accounting for 69 of 2,286 delegates to the Republican convention in August, at which the nominee will formally be selected. Mr Romney won by a big margin: 47% to 35%. Because of the complicated electoral rules in Illinois and many other states, that will bring him at least two-thirds of the delegates from the state. It also marks the first time that he has drubbed Mr Santorum in the Midwest, after narrow wins in Michigan and Ohio and defeats in Iowa and Minnesota. Mr Santorum did his best to expand his appeal beyond the most conservative voters, talking in histrionic terms about the need for smaller government. "This is the most important election of your lifetime," he intoned at a rally in Peoria, the supposed navel of middle America. "Freedom [is] at stake," he tweeted on the morning of the primary. But he had already fluffed his lines, appearing to suggest that the unemployment rate was not that important (compared with preserving America's founding principles, he meant). Disappointingly for Mr Santorum, Peorians seemed to have faith in Mr Romney's ability to repair the economy. People for whom that was the most important issue voted for him overwhelmingly, according to exit polls. They also had misgivings about Mr Santorum's emphasis on social issues. At an event he held also in Peoria, a veteran said of his fixation with abortion: "It's the last thing we should care about. If we keep spending, we are going to end up like Greece. Yet like a moth to the flame Mr Santorum keeps returning to such topics, and all the controversy that comes with them. During a speech he gave at a religious school in the Chicago suburbs, two men in the audience stood up and kissed, prompting predictable hostility from the crowd. Mr Romney has won over half of the delegates awarded so far. That pace, if sustained, will be more than enough to secure him the nomination outright, although probably not before the final primaries in May and June. His rivals, by contrast, would need to improve their showing dramatically, winning the lion's share of the remaining delegates simply to deny Mr Romney outright victory. And they would have to do that in unfavourable states like Maryland, New York and California. The prospects for the two other candidates, Newt Gingrich and Ron Paul, look hopeless; but neither of them shows any sign of being ready to concede. Both Mr Paul and Mr Santorum argue that they have actually won more delegates than estimated in the caucus states. This could be true (those delegates have not actually been assigned yet), but the difference would be far too small to alter the dynamics of the race. Mr Gingrich, for his part, seems to enjoy campaigning and to bear a grudge about how Mr Romney and an allied Super PAC ended his time in the sun with cloudbursts of negative advertising. Moreover, even if Mr Romney's nomination is in the bag barring some unexpected reversal, his position is hardly commanding. His biggest wins have tended to be in places that either vote reliably Democratic in presidential elections, such as Illinois and Massachusetts, or don't vote at all, such as Guam and Puerto Rico (which gave him almost 90% of the vote on March 18th). He still struggles to win the support of poorer, less educated, more conservative and more religious voters. On March 24th he is likely to lose the next state to vote, Louisiana. His long, hard march to the nomination continues. Explore our map and guide to the Republican candidacy race