The absolute last person who would ever have taken this approach is Abraham Lincoln. Yes, Lincoln’s presidency was the product of a time period when his original party (the Whigs) unraveled and was replaced by a more principled party (the Republicans). This is what some of the Lincoln Project folks say they would like to see. But it is where the similarity ends. In 1848, the Whigs nominated Zachary Taylor for president. While parallels between Taylor and Trump are overstated, Taylor was a political novice of vague political principles, and because he was a large-scale Louisiana slaveholder who would not campaign against slavery, Charles Sumner and other “Conscience Whigs” refused to support Taylor. The Conscience Whigs were, in 2016 terms, Never Taylor. Lincoln didn’t join them. He and William Seward, later his secretary of state, both remained faithful Whigs and stumped for Taylor against Lewis Cass, a northerner running on a “popular sovereignty” platform more favorable to the expansion of slavery. As it turned out, Taylor in office was much more hostile to the pro-slavery Democrats than anticipated — like Trump, he was politically radicalized by partisan opposition — and grew to detest his former son-in-law Jefferson Davis.
In fact, Lincoln would be one of the last Whigs to abandon his party; only when it was clearly no longer a useable vehicle for pursuing his causes did he turn to the Republicans. The Republican coalition he built in 1860 was constructed on standing together to do common things; Lincoln was careful to make room in his tent for anyone who agreed with him, even slaveholders and former anti-immigrant Know-Nothings. He did not hold personal political grudges. In 1854, as the Whigs were unraveling, Lincoln was arguing that the best defense against expanding slavery into the territories was to defend the Missouri Compromise and the Compromise of 1850, even with all of their flaws (including the Fugitive Slave Law). He gave a speech in Peoria in October 1854 arguing that those who wished to preserve the Union should work together and not turn up their noses at standing with people they otherwise disagreed with — so long as they stood together on issues of agreement: