Open Voter Registration. At the time they register, all voters shall have the freedom to choose whether or not to disclose their party preference. No voter shall be denied the right to vote for the candidate of his or her choice in either a primary or a general election for statewide constitutional office, the State Legislature, or the Congress of the United States based upon his or her disclosure or nondisclosure of party preference. Existing voter registrations, which specify a political party affiliation, shall be deemed to have disclosed that party as the voter’s political party preference unless a new affidavit of registration is filed.