Despite your quote...which is true...Reagan was pragmatic and understood the art of politics which requires some compromise...he also appealed to a broad range of voters...big tent.
He appealed to the better angels of our nature. He gave no ground on abortion, he gave no ground in his defense of capitalism or his opposition to Marxism, he gave no ground on a single principle. He governed with a democrat legislature and was forced to give-to-get once he was in office.
That's the art of politics. Not giving it away to get elected. If you can't sell the truth against the lie, if you need to make concessions to the liars to get your power, you've already lost.