Manifest Destiny may be politically wrong term, as there are perceived winners and perceived losers (especially without any of their fault other than being at wrong place with wrong crowd) ;
But make no mistake, Space is new manifest destiny.
Initially we thought earth is extremely special we have everything for life. But the more we venture out the more we realize it is not so special,
We thought earth is with abundant water, ==> Wherever we poke on space, we are finding water! (Moon, Mars, exoplanets, asteroids etc..)
We thought milky way is our galaxy and the galaxy with one or more possible in the universe. But you adjust Hubble telescope lenses and you view ten’s or hundred’s of galaxies. They are everywhere.
There are billions of stars, three times more planets, three times more moons, ten times more asteroids. Probability of colonizing few of them is very high, provided humanity plays its cards well.
Current Capitalism, Current religion are not enough to drive humanity onto space. We need better tools.