SAN ANTONIO — Looking to make inroads with the rising number of Hispanic voters, conservative activists are offering English classes, health checkups and courses to help Spanish-speakers earn high school diplomas. Picking up part of the tab: Charles and David Koch.

The billionaire industrialists are working to patch a gaping hole in the GOP coalition that could spell a generation of irrelevance if Republicans cannot build some credibility with Hispanic voters, who typically shun the GOP. The fast-growing group could have tremendous sway in American politics for years to come. Party elders have acknowledged their struggles to win over Hispanic voters, who as recently as 2004 were roughly split in party preference.

Enter the Libre Initiative, an organization that has collected millions from the Kochs’ political network. Libre, which is pronounced LEE’-bray and means “free,” pushes a message of limited government and economic freedom between lessons on how to build family-run businesses and prayer breakfasts with Hispanic pastors.