<apex:selectList value="{!SelectedNomination}" size="1" id="a">
   <apex:selectOptions value="{!contactlist}"></apex:selectOptions>
</apex:selectList>

public List<Nominator__c> Nominators = new List<Nominator__c>();

public List<SelectOption> contactlist
{

    get
    {

        String state =
             application.Congressional_State_Territory__c.substring(0,2);

        Nominators = [Select Id, Name, Class_Year__c, Contact_Name__c,
              Nominator_Code__c, Nominator_Type__c from Nominator__c WHERE
              FirstTwoLetters__c =: state and Nominator_Type__c=
              'Congressional - House' and Class_Year__c =:
              application.Class_Year__c and Status__c =:'Active' ];

        contactlist = new List<SelectOption>();

        for(Nominator__c nom : Nominators)
        {
            contactlist.add(new SelectOption(nom.Id, nom.Name + ' ' +
            nom.Contact_Name__c));
        }

        **contactlist.sort();**
        return contactlist;
    }
    set {}
}

Nominators = [Select Id, Name, Class_Year__c, Contact_Name__c,
              Nominator_Code__c, Nominator_Type__c
              from Nominator__c
              WHERE
              FirstTwoLetters__c =: state
              and Nominator_Type__c= 'Congressional - House'
              and Class_Year__c =: application.Class_Year__c
              and Status__c =:'Active'
              ORDER BY Name ASC] ;