The billionaire George Soros and other liberal donors will bankroll a new $15 million campaign to mobilize Latinos and other immigrants this fall, hoping to channel outrage at the political rhetoric of Donald J. Trump and other Republicans into a surge of votes for Democratic candidates in November.

Strategists involved said the new spending would be the largest Democratic voter-turnout effort ever devoted exclusively to Latino and immigrant voters. Most of the money will be spent through organizations in Colorado, Florida and Nevada, states with large or growing Latino and Asian populations that will be pivotal in the presidential race and in the battle for control of the Senate.

The outreach, which will be coordinated through a new “super PAC” called Immigrant Voters Win PAC, will be more explicitly political and partisan than past efforts, the strategists said: The goal was to not only turn out committed Latinos already voting Democratic but also find and persuade immigrant swing voters. Ultimately, organizers hope to get at least 400,000 new Democratic voters to the polls in November.