She fucked the country so hard we're still feeling the effects now, she won for various reasons. An uplift in popularity after the Falklands, she got a lot of women's votes for being a woman and people didn't trust the Labour party after the 70s. Much like Conservatives are in power now, and appear to have popularity because people don't trust lib dems or labour.
Love or hate her policies, you have to admit they were influential. They completely changed Labour's approach as well. People always accused Blair of being Thatcher-light. But the basic approach was to modify the most harmful effects of her policies, but to keep the basic ideas intact.