WASHINGTON—Sen. Ted Cruz, R-Texas, dominated WORLD’s ninth evangelical insiders survey, which found a large majority of participants ready to vote for a third-party candidate if Donald Trump wins the Republican nomination. The new findings are part of a monthly survey of 103 evangelical leaders and influencers, 81 of whom participated in March. The results are not scientific or representative of all evangelicals but provide a glimpse into how some influential evangelicals are leaning in the 2016 presidential race. Sen. Marco Rubio of Florida came out on top in the first eight surveys, but after his exit from the race last...