Actually, according to the IRS, a political non-profit can qualify for tax exemption status as long as the MAJORITY of their activities are exempt functions.
From
www.irs.gov.
Exemption Requirements - Political Organizations
A political organization subject to section 527 is a party, committee, association, fund, or other organization (whether or not incorporated) organized and operated primarily for the purpose of directly or indirectly accepting contributions or making expenditures, or both, for an
exempt function.
A political organization must be
organized for the primary purpose of carrying on exempt function activities. A political organization's primary activities must be exempt function activities.
A political organization may engage in activities that are not exempt function activities, but these may not be its primary activities.
To be exempt, a political organization must file a timely
notice with the IRS that it is to be treated as a tax-exempt organization.
Exempt Function - Political Organization
The exempt function of a political organization is influencing or attempting to influence the selection, nomination, election or appointment of an individual to a federal, state, or local public office or office in a political organization. The election of Presidential or Vice-Presidential electors is also part of the exempt function of a political organization. Activities that directly or indirectly relate to or support an exempt function are exempt function activities.