He won more of the Republican vote than the 1st, 2nd and possibly even third placers combined (maybe off by a point or two). Whether you want to call it a plurality or a majority or whatever, Trump clearly dominated it to the same degree as he did independents. 70 percent of the total vote, by the way, also claimed to be conservative, with 25 percent of them calling themselves "very conservative." Trump dominated them too. 30 or so percent reported as Moderators, and, of course, Trump dominated them as well. His only real threat was with the moderates, where Kasich had 28 percent and Trump only 32 percent of them. New Hampshire only had 30 percent of its Republican voters identify as moderate. You will not be having this many self-report as such in South Carolina.
If the GOPe candidates all coalesce into one candidate, Trump might have some trouble in more liberal states, but then Trump so dominates the conservative vote-- and the conservative vote so dominates the primary process to begin with-- that it probably won't be a problem, and Trump's numbers will probably even grow even bigger among conservatives once they realize that they must unify behind the strongest conservative in the race as these other people drop out.
Two-thirds continue to vote for someone else. The question is, will these votes coalesce behind someone else, or go to Trump? I expect that they will gravitate to someone else.