Life imitates art, they say, but for Fred Thompson the two have long been barely distinguishable. His career has played out like a tightly woven thread, crisscrossing the seam between real-life political dramas and the make-believe variety concocted in Hollywood.

As an ambitious lawyer 33 years ago, he played a small but significant part in the investigation of Richard Nixon over the Watergate scandal. A decade later, at the age of 40, he got an improbable late break into acting when he was invited to play himself as a prosecutor rooting out political corruption in Tennessee. That chance led to a series of increasingly prominent roles in films with mostly political themes: alongside Kevin Costner as Director of the CIA in No Way Out, with Clint Eastwood, as the White House chief of staff in In the Line of Fire, as a submarine commander in the Sean Connery Cold War thriller The Hunt for Red October.

In the 1990s he switched effortlessly back into real politics, winning election as senator from his home state of Tennessee. In the Senate he led the investigations into the questionable fundraising strategies of Bill Clinton and Al Gore. But in 2002, apparently disillusioned with Washington, he left politics and went back to acting. And so for the past five years he has been one of the most familiar faces on television – playing Arthur Branch, the gruff-voiced, nononsense district attorney who leads a team of prosecutors on the long-running NBC crime drama Law & Order.

It looked as if he was content to end his double life on the more lucrative, fictional entertainment side of the divide. As he likes to joke: “I left the Senate because, after eight years in Washington, I yearned for the reality and sincerity of Hollywood.”

But, quite suddenly, Thompson is about to make the biggest and potentially most consequential switch yet between the art of his career and the life it has been imitating all along. If all goes according to plan, he will announce in the next few weeks that he is running for President.

Pollsters and political insid-ers are agreed that this will be no quixotic, long-shot candidacy. He is already polling above 10 per cent in the crowded Republican field, even though he is not yet a candidate. When he announces his candidacy, probably some time this month, he is likely to jump straight into first or second place among the dozen or so contenders for the Republican nomination.

His timing, as you would expect from an habitué of Hollywood, is impeccable. To many disillusioned Republicans, their morale battered by an unpopular President, an endless war in Iraq, and a crushing loss in last year’s mid-term congressional elections, Thompson is more than just an interesting presidential hopeful. He is a saviour.

The 2008 election is still 18 months away, and the party has an array of attractive potential candidates, including Rudy Giuliani, the former Mayor of New York, John McCain, the Arizona senator and Vietnam war hero, and Mitt Romney, one-time Massachusetts governor with matinee-idol looks. But as they look towards next year’s election, Republicans are deeply gloomy about their chances against a resurgent Democratic Party, led, presumably by either Hillary Clinton or Barack Obama. Conservatives, the core of the Republican vote, are especially despairing. None of the leading three Republican candidates can reliably be called a conservative. Giuliani is too liberal on issues such as abortion; Romney has changed his mind too many times on the same issues; and McCain is not trusted, after he ran a full-throated campaign against George Bush in 2000.

But Thompson seems to fill the gap. He talks, in a reassuring deep Southern growl, about how he got into politics because he read Conscience of a Conservative, the personal manifesto of Barry Goldwater, the Arizona senator who was crushed in the 1964 election by Lyndon Johnson, but who sparked the beginning of the conservative revolution.

In his eight years in the Senate, Thompson was a reliable conservative, voting for restrictions on abortion, against tax increases and for cuts in government spending. He invites inevitable comparison with Ronald Reagan, another conservative actor who made it big in politics. He is full of folksy aphorisms about what is wrong with the country, and the appealing message that conservatism must return to its core values: respect for the individual and national security.

Lamar Alexander, who succeeded Thompson in the Senate, is effusive about his charisma. He told me that the current Thompson mania amounts to a conscription of the man by the Republican grassroots.

“This is the closest I have seen to a draft of a presidential candidate in 40 years in politics,” he says.

What really excites his supporters is that, as a familiar and likeable Hollywood face, Thompson is that rare bird, a conservative with real broad appeal to voters across party lines. In the wreck of the Bush presidency, is it possible that they may still manage to pick a gem from the debris?

The hopes invested in Thompson were palpable last week at a party gathering in Stamford, Connecticut, a busy suburb of New York City. Thompson was in town ostensibly as the keynote speaker at the Prescott Bush Awards Dinner, named after the grandfather of the President, who was a Connecticut senator half a century ago. But he was really there to give another of the occasional, tantalising glimpses of his potential candidacy that he has offered in the past month. The event was sold out; the 600 or so party faithful crammed into the international ballroom of the Sheraton Hotel numbered far more than had attended recently to hear from the real candidates Giuliani and McCain.

As he was introduced, to a thunderous ovation, a chorus of “Run, Fred, Run” welled up from the back of the room. When the applause had died, a woman’s voice cried out, beseeching him to make official his ambition. The proto-candi-date savoured the moment with a tease: “OK, let’s get the announcement out of the way first,” he said, and paused as an expectant silence fell. “Yes, Law & Orderwill return for an 18th season in the fall,” he wisecracked. Then, curiously, it was rather downhill all the way. For all his Hollywood training, Thompson is no orator. He ambled through his remarks in a slightly desultory way, even fumbling at times for his lines.

He may have overdone the Southern folksiness a bit. Speaking at one point about al-Qaeda, and the need to keep up the fight against Islamist terrorism, he said: “They say the cat won’t sit on a hot stove twice. But it won’t sit on a cold stove, either.”

This was evidently supposed to be a piece of Southern wisdom but it had his Connecticut Yankee audience somewhat nonplussed. Perhaps it was because expectations were so high – he is box office, after all – but there was an unmistakeable sense of disappointment among the faithful afterwards.

“I think, given who he is, people came expecting maybe a B-grade message and an A-grade presentation,” says Dick Foley, a big cheese in Connecticut Republican circles. “Instead they got an A message but a B presentation.” The message, it’s true, seemed to resonate. While it ticked all the necessary boxes of Republican politics – the importance of the war on terror; attacks on Democrats for wanting to “surrender” in Iraq; the need for tax cuts – it focused more on what Thompson said are the core values of conservatism.

There was a “rumbling” out in the country, he said, a mood of discontent among not just Republicans but Democrats, too. In Connecticut, whose Republicans are among the nation’s most moderate, he carefully avoided references to issues such as abortion or guns, and dealt only a glancing blow at the current hot object of conservative rage: immigration.

Thompson has clearly realised that the key to victory for him – his unique selling proposition, if you like – is the messenger, not the message.

Winning next year is going to be a tall order for Republicans. It’s hard to see how they can turn the mess in Iraq to their advantage; their decade in control of Congress and what will be eight years in the White House has created a powerful desire for real change.

They will not win simply by restating a message of old-fashioned conservatism. Thompson’s gamble is that the party’s best shot will be to elect someone who, quite frankly, looks the part.

“He has a presidential bearing,” says Senator Alexander. “That counts for a lot in politics.” It is this personal quality that mostly seemed to appeal to Republicans in Connecticut. It may not have been the most scintillating performance, and he will clearly have to hone his speaking skills. But it is Thompson the man who will make his pitch to the nation, not Thompson the predictable politician.

For women voters especially, who have turned away from the Republicans in the past few years, this may be the real source of his political appeal. “On TV and in movies he plays these reassuring, older, father-like figures,” Rebecca Adams tells me after listening to him speak. “And that comes across in real life. A lot of women want someone they can look up to as President, a moral authority in public life.”

Dependable, authoritative, reassuring. It is the role that Fred Thompson has been playing in a lifetime on screen. In the next few months Americans will come to see whether he can pull it off, one last time, in real life.

Election run-in

Iowa caucus: January 14, 2008

Nevada caucus: January 19

New Hampshire Primary: January 22

Florida Primary: January 29

South Carolina primary: February 2

“Tsunami” Tuesday: (Primaries held in 18 states): February 5,

Republican Convention: (to declare official party nominee): September 1-4

Election day: November 4

Thompson’s career – and rival candidates

1967: Obtained law degree from Vanderbilt University in Nashville, Tennessee.

1969-72: Worked as an assistant US Attorney.

1973-74: Co-chief counsel, Senate Watergate committee.

1975-1992: Worked as a lobbyist in Washington, DC.

1984: Began his film career portraying himself (the main character's lawyer) in the in the film Marie, based on a true story.

1990: Appeared in several major films, including No Way Out, Cape Fear, The Hunt for Red October, Days of Thunder, In the Line of Fire and Die Hard 2: Die Harder.

1994: Won special election to the US Senate from Tennessee; elected to first full term in 1996.

2002: Decided not to seek second term as a senator.

2002-present: Plays District Attorney Arthur Branch on the TV series Law & Order and its spin-off programmes.

Republican presidential candidates for 2008:

Senator John McCain (Arizona).

Senator Sam Brownback (Kansas).

Former Governor Mitt Romney (Massachusetts).

Former Governor Mike Huckabee (Arkansas).

Former Governor Jim Gilchrist (Virginia).

Former Governor Tommy Thompson (Wisconsin).

Former Mayor Rudy Giuliani (New York).

Congressman Duncan Hunter (California).

Congressman Tom Tancredo (Colorado).

Congressman Ron Paul (Texas).

(Anna Stroman)

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