More on the “why” of the Lincoln Project, explained by Vox. This point is apt:

Liberals who oppose the Lincoln Project object to its core conceit: Trump, and Trumpism, are a cancer on the Republican Party, and by removing him and his ideas, things can perhaps go back to normal. In the conservative group’s mindset, Republican presidential candidates like John McCain and presidents like George W. Bush exemplified the best of American conservatism, while Trump is an aberration: a former reality show host with divorces, affairs, and affronts to “traditional morality” aplenty.

But as historian Eric Foner argued in 2016, Trump can be seen as “the logical conclusion of a lot of things the Republican Party has been doing” for decades, with predecessors like Richard Nixon’s “law and order” presidential campaign, rife with racist implications, and populist appeal as a businessman railing against Washington corruption. To many liberals, Trump isn’t an aberration; he’s the culmination of a decades-long political project.