Many politicians before and after Taylor had well known military careers as war heroes and he was no exception. What is exceptional however is that his very FIRST political office was President of the United States.
It's understandable that many Americans don't want career politicians as President, but it's hardly imaginable that someone who never held any political position could be elected to the highest office in the land (think of the flack Sarah Palin got and she was the mayor of Wasilla!). Taylor spent nearly 40 years in the military before being nominated by the Whig party.
The Whig party calculated that having a Southerner and Northerner on the same ticket would be a good political move in this divided time and they were right. The irony is that as a career military man, Taylor didn't foster the strong Whig beliefs that they might have expected- at least none that he shared publically during the campaign.
Taylor, like Harrison got elected because most of what was known about him was nothing more than that he was a war hero. Taylor took the opposite approach as Polk in the election before and rather than being the candidate to make a bold stand on his beliefs, Taylor would take almost no public stands on the issues of the day other than that he believed in the constitution. He let people decide for themselves what his beliefs were and seemed to attract voters on conflicting sides of the same issue.
Many politicians have tried this tactic throughout world history, but I guess it takes a newbie to pull it off.