Meryl Streep as Margaret Thatcher and Jim Broadbent as Dennis Thatcher in Phyllida Lloyd's film “The Iron Lady.” (Alex Bailey/PHOTO BY ALEX BAILEY/COURTESY THE WEINSTEIN COMPANY)

LONDON — Most of my British friends won’t see The Iron Lady on principle. “Her again?” is their feeling — not about its star, Meryl Streep, but its title character, former British Prime Minister Margaret Thatcher.

As middle-aged, generally left-leaning types who came of age in the 1980s, when Thatcher ruled supreme, they loathe “Maggie” and everything she stood for. In their minds, she ruined the British public education system, decimated trade unions and privatized the nation.

I myself nearly gave the movie a pass, though not for political reasons. Other than Streep – whom everyone agrees gives an amazing performance – most people, whether reviewers or friends - seemed to feel pretty “meh” about the film itself. So I figured that I could just wait and rent it once it came out on DVD.

It was my 80 year-old mother, herself a former actress, who set me straight and motivated me to go see “The Iron Lady” in a theatre. And I’m so glad that she did.

The criticisms of the film tend to fall in one of three categories. There are those – like Prime Minister David Cameron – who feel that it’s disrespectful to make a movie about a historical icon like Thatcher while she’s still alive, particularly when a major subject of the film is Thatcher’s dementia.

As a staff writer for London’s Daily Telegraph put it, “She deserves to be treated with as much dignity as anyone else. This is precisely what the film, in depicting her in the grip of dementia while she is still alive, fails to do.” I’m sympathetic to this criticism, although from my perspective (see below), this is precisely the film’s greatest strength.

A second criticism I’ve heard voiced (interestingly, often by friends of mine who haven’t seen the film) is that it’s “not about politics.” That is complete and utter rubbish. It’s true that the film moves back and forth between contemporary scenes of Thatcher coping with old age and dementia in her home (often sparring verbally with her deceased husband Denis Thatcher, played by Jim Broadbent) and her rise to power from humble shop-keeper’s daughter to first (and only) female Prime Minister of the United Kingdom.

But to suggest that the film isn’t political because – to paraphrase a reviewer in The Independent, it’s about Thatcher, not Thatcherism – is, in my opinion, misguided. There are plenty of suggestions in the film that Thatcher was a thoroughly polarizing political figure in her day, including real footage from the 1984 miners strike. Thatcher’s growing ideological rigidity and isolation are also in plain view. I was able, because of the film, to link Thatcher’s fierce, zero-tolerance attitude towards the Irish Republican Army – two of whose terrorist attacks she witnessed personally – to her equally fierce decision to defend the Falkland Islands when Argentina invaded them in 1982. In both cases, she perceived the attacks as striking at the core of British sovereignty. I’m not sure that I would have made that link without seeing the film.

The other way that the film is overtly political – and here it could not be better timed – is in highlighting the treacherous road women need to tread in order to be taken seriously in politics. Was Thatcher hyper-ambitious, as the film suggests? You betcha (to coin a phrase from another well-known, hyper-ambitious female politician.) Did she need to be? Absolutely. It’s tempting to think of this subject as a quaint concern of the past. But as Americans know, based on last week’s all-male hearing on contraceptives in the U.S. Congress, that battle is far from over. And in a country where women are still quite under-represented in parliament, it’s a message that most Brits would do well to contemplate some more.

Which brings me to the final criticism I’ve heard about the movie – which is that it humanizes Thatcher. And that is, for some, quite simply unbearable. To which I say, sure it does. And that’s precisely why Streep deserves the Oscar for Best Actress this year.

It’s not just that she gets Thatcher and reproduces her in an uncanny fashion on screen. It’s that she gets what it’s like to grow old. Anyone who’s ever had an aging parent (I do), had a parent die (I have) and/or lived with someone with Alzheimer’s and/or Dementia (ditto), can relate to this remarkable performance because it underscores what it means for all of us – famous and not-so famous – to gradually lose control over our bodies and our minds. It’s sad, it’s terrifying and it’s universal.

So thanks, Mom. I’m glad I listened to you.

Delia Lloyd – a former correspondent for Politics Daily - blogs about adulthood at . You can follow her on Twitter @realdelia .