An arc towards justice or is it an oscillating towards the right?

Donald Trump at his worst is cruder, truly less informed than the other Republican presidents that have been pushing this country to the right since Richard Nixon. Getting rid of him, though desirable, won't change directions, does not restore some nostalgic normality, except maybe with a friendlier face and more towards "civility" which will help corral the fence sitters and independents. But if a Democrat wins the White House in 2020 what would it mean to return to "normality"? A return to neoliberal politics? To cold war thinking? To the belief in American Exceptionalism? That we are good but must fight against all evil in the world? We've had all that since the end of WWII.

I question the quote by M.L. King Jr. -- “The arc of the moral universe is long, but it bends toward justice.”-- it's a quote that President Obama liked to remind us of. (But an arc rises and falls, it's a section of a circumference where the first and second points of the arc land at the same level). So as metaphor I find that maybe it's not that useful? Lincoln arguably was our greatest President but no President after Lincoln pushed for changes in the country until FDR did to help move the country during the depression and after towards social justice sadly not for all though for many. No other President sought to improve the lot of poor and middle class Americans until he did.

Yes there have been positive social changes though at a snail's pace and the "ancien regime" of racial and sexual abuse and violence continues in hopes that any positive changes can be rolled back to some idyllic age of white male dominance and the myth of self-reliance, guns included. So instead of an arc since FDR our country's changes have been oscillations at best, oscillating toward the right, towards corporate control, towards religious purity, and fulfilling the dreams of Empire.