Candidates of the various political parties for nomination, except for the office of President of the United States, who receive a plurality of votes of their party electors in the State, or in the political district, as the case may be, at the primary election, together with the candidates for the office of presidential elector nominated as herein provided, shall be candidates of their respective parties, and it shall be the duty of the proper county boards to print their names upon the official ballots and ballot labels at the succeeding election: Provided, That when a candidate for nomination shall have died before or on the day of the primary election and shall nevertheless receive a plurality of votes of his party electors cast for the office for which he sought nomination, then no candidate shall have been nominated for the office at such primary and a substituted nomination may be made in the manner hereinafter provided.