The word for today is…
espouse (verb) – Adopt; champion, advocate.
Source : The Free Dictionary
Etymology : As you might guess, the words espouse and spouse are related, both deriving from the Latin verb spond?re, meaning “to promise” or “to betroth.” In fact, the two were once completely interchangeable, with each serving as a noun meaning “a newly married person” or “a husband or wife” and also as a verb meaning “to marry.” Their semantic separation began in the 18th century, when the noun espouse fell out of use. Nowadays, espouse is most often seen or heard as a verb used in the figuratively extended sense “to commit to and support as a cause.” Spouse continued to be used in both noun and verb forms until the 20th century, when its verb use declined and it came to be used mainly as a noun meaning “husband or wife.”