Erika Kirk Praises Spencer Pratt's L.A. Mayoral Run

Spencer Pratt has nailed down another huge supporter ... because Erika Kirk's backing him -- though she won't be able to add to his vote total directly.

Charlie Kirk's widow praised Spencer's run for office in a post to X Thursday ... writing it doesn't matter whether he wins or loses -- he's a true American for even throwing his hat in the ring and hoping to become part of a solution.

Yes, Spencer's running an unconventional campaign, Erika admits ... but she thinks people are gravitating to him because he's not speaking like a career politician -- he's speaking like a citizen who "sees and deeply understands how fragile the simple things in life are when leadership fails."

EK says this country's built on citizens stepping into the political arena to challenge "a failing system" like the one which has "destroyed Los Angeles -- and she hopes moments like these can inspire more Americans to get involved and stand up for the country.

It's a glowing endorsement ... and the most direct support Erika can provide for Spencer because she famously lives in Arizona -- and can't actually vote for him.

She's got a huge audience though ... so, those on the fence about the guy who love Erika may be swayed by her appeal.