Abraham Lincoln pushed some deeply unpopular things through. The 13th Amendment was a good example. Despite getting passed and ratified, there was deep ambivalence to emancipation. He portrayed it as a necessary war measure (it wasn't) and used all sorts of bribery and backroom manuevers to get it past.
Its very difficult to read Lincoln. Was he a political opportunist, who took positions and abandoned them according to the times? Or was he a passionate believer in his cause, but canny enough to know that he would have to accomplish it by careful steps, and carefully orchestrated the conditions necessary?
And of course there was Washington. Many people wanted him to be king. He always had to fight people who wanted him to be more than the constitution allowed.
Kennedy and Johnson and the Civil Rights Act is another good example.