What I mean by drafted is: someone who had not announced their candidacy or campaigned in the primaries, but who, after no first ballot winner at their party's national convention, was picked to be the nominee.
In case anyone is interested, Adlai Stevenson was drafted by the Democrats at the 1952 convention. https://en.wikipedia.org/wiki/United_States_presidential_election,_1952#Democratic_Convention
Only example I've come across at this point.