With elections imminent on both sides of the Atlantic Margaret Thatcher has found herself exactly where she prefers to be: in the limelight, dispensing patronage to those who swear fealty to her particular brand of fundamental conservatism.

A string of Republican hopefuls have been making the pilgrimage to a terraced home in Chester Square, London, to pay their respects to Lady Thatcher, have their photograph taken with her, and hope that some of her magic dust brushes off on them.

Lady Thatcher was Britain’s most successful electoral politician in the modern age, winning three elections in a row and lasting longer in office, 11 years, than anyone since Lord Liverpool, the prime minister who hung up his spurs in 1827 having been prime minister for 15 years.

But it is not merely Lady Thatcher’s electoral technique that her visitors Rudy Giuliani, Fred Thompson, and Mitt Romney, have come to emulate but her link to what, after seven years of neo-conservatism in the White House has come to be thought of as The Golden Age of Conservatism, when Ronald Reagan was in the White House, Mrs Thatcher was in Downing Street, and all was well with the world.

For eight full years Reagan and Lady Thatcher overlapped, and their bond of friendship and common understanding of what needed to be achieved provided an admirable clarity of purpose, the absence of which has provoked a wave of nostalgia for those long lost sunny times. For Mr. Giuliani, as with the others, the Thatcher meeting was ceremonial, an act of obeisance that subliminally demonstrated to old fashioned conservatives back home that, notwithstanding his views on social issues and his personal life, he is a true believer.

In Britain, where Lady Thatcher has long been a contentious, divisive figure she has in recent times overcome years of unpopularity and emerged as the Grand Old Lady of Downing Street. For much of the electorate, too young to remember her assertive and combative style of government, she symbolizes the good old days, when leadership was certain, enemies were beaten, and problems solved.

Which is why it was so canny of Gordon Brown, the Labour prime minister, to praise Lady Thatcher for being a “conviction politician” — that is someone who does not need polls and think tanks to suggest policies — and invite her round for tea at 10 Downing Street. The event turned out to be all that Labour strategists, preparing the way for a snap election which will likely be announced next week, could have wished for.

Gordon Brown was in his Sunday best suit, standing at the famous black painted door, when Lady Thatcher emerged from her limousine in a shimmering red dress. For all the years of her premiership, Lady Thatcher had stifled her preference for red — the Labour color — in favor of a strident Tory blue.

Her appearance in flaming scarlet was an eloquent statement to the country that she believed Britain to be safe in Gordon Brown’s hands for another five years and elicited shouts from those paid by news networks to holler questions from a distance, “Mrs. Thatcher, are you joining the Labour Party?”

Lady Thatcher spent two hours having afternoon tea with Gordon Brown and his wife Sarah, who accompanied the grande dame back to her waiting limo as if she were the sainted mother-in-law come on a rare visit.

The Conservatives, outsmarted, were all over the place. Lady Thatcher has already let be known her antipathy toward her successor David Cameron, who has edged the party away from her brand of undiluted market based conservatism towards the center. Her fearsome henchman Norman Tebbit added bite by suggesting that the Brown visit was a “perfect response” to Mr. Cameron’s attempts to become the “heir to Blair.”

While one top Tory was obliged hurriedly to make clear, “We’re not dumping Margaret Thatcher,” William Hague, the shadow foreign secretary, took a leaf out of Lloyd Bentsen’s book when debating the callow Dan Quayle. “You may fawn now at the feet of our greatest prime minister,” Mr. Hague told Mr. Brown from the Conservative conference this week, “but you are no Margaret Thatcher.” How the old lady must have smiled.

The problem for today’s voters on both sides of the Atlantic is that no one standing for election is either a Reagan or a Thatcher. Such figures are thrown up by history, like Franklin Roosevelt and Winston Churchill, at the right time, fully formed, ready for action. Other circumstances bring forth other leaders.

For British voters, Tony Blair was the perfect antidote to the Thatcher years. For Americans, George W. Bush seemed such a refreshing change from eight years of the Clintons and Al Gore.

Today, voters still crave strong, clear leadership, which is why each Republican candidate in turn lays claim to the Reagan inheritance.

Only Rudy Giuliani, however, has demonstrated anything like Reagan’s bold leadership, in the wake of September 11, when we all desperately needed someone to rally around. Whether six years on he can evoke that same defiant spirit will determine whether he can lead the GOP into the general election.

Mr. Wapshott’s “Ronald Reagan and Margaret Thatcher: A Political Marriage” will be published on November 8 by Sentinel, an imprint of Penguin USA.