Question

In the recent past, primaries were used both to select delegates and to...

Answer 1

In the recent past, primaries were used both to select "delegates" and to "allow party members to express their nominee preferences." And the delegates to a party's national convention are selected through primary selections and Caucuses. The delegates all attend the national party convention at the end of summer of beginning of fall.
Hope this helps. 

Answer 2

Answer: allow party members to demonstrate or express their nominee preferences

Explanation:

Primary elections are known to be type of election in which members of a political party come together to choose and vote for nominees among themselves which will represent the party in the general election. Furthermore, this form of election allows members to vote for nominees of their choice. Thus, it is a preparatory action in selecting or nominating candidate for the general election.