The On The Issues page isn't very current.
Sen. Bernie Sanders (I-VT) is renewing his efforts to rid the country of Citizens United by introducing a new constitutional amendment that would overturn the Supreme Courts decision.
The amendment states:
SECTION 1. Whereas the right to vote in public elections belongs only to natural persons as citizens of the United States, so shall the ability to make contributions and expenditures to influence the outcome of public elections belong only to natural persons in accordance with this Article.
SECTION 2. Nothing in this Constitution shall be construed to restrict the power of Congress and the States to protect the integrity and fairness of the electoral process, limit the corrupting influence of private wealth in public elections, and guarantee the dependence of elected officials on the people alone by taking actions which may include the establishment of systems of public financing for elections, the imposition of requirements to ensure the disclosure of contributions and expenditures made to influence the outcome of a public election by candidates, individuals, and associations of individuals, and the imposition of content neutra limitations on all such contributions and expenditures.
SECTION 3. Nothing in this Article shall be construed to alter the freedom of the press.
http://www.politicususa.com/2015/01/21/bernie-sanders-files-constitutional-amendment-overturn-citizens-united.html