Our form of government is a republic. The specific members of the House of Representatives, US Senate and the US President are elected to represent our voice within the Legislative and Executive branches of our federal government.
Today, campaign laws allow donations to be made to potential candidates whom could not legitimately represent the donor in either the House of Representatives or the US Senate because that donor is registered to vote outside the district of the candidate form who they have donated money. This allows candidates to be influenced by and represent donors form who they cannot represent and whose rights they are not in a position to protect.
By disallowing donations to candidates who could not represent the donor, we are protecting the rights of the electorate.