42 USC 9851 - Political activities

(a) State or local agency 
For purposes of chapter 15 of title 5, any agency which assumes responsibility for planning, developing, and coordinating Head Start programs and receives assistance under this subchapter shall be deemed to be a State or local agency. For purposes of clauses (1) and (2) of section 1502(a) of such title, any agency receiving assistance under this subchapter shall be deemed to be a State or local agency.
(b) Restrictions 

(1) In general 
A program assisted under this subchapter, and any individual employed by, or assigned to or in, a program assisted under this subchapter (during the hours in which such individual is working on behalf of such program), shall not engage in
(A) any partisan or nonpartisan political activity or any other political activity associated with a candidate, or contending faction or group, in an election for public or party office; or
(B) any activity to provide voters or prospective voters with transportation to the polls or similar assistance in connection with any such election.
(2) Registration 
No funds appropriated under this subchapter may be used to conduct voter registration activities. Nothing in this subchapter prohibits the availability of Head Start facilities during hours of operation for the use of any nonpartisan organization to increase the number of eligible citizens who register to vote in elections for Federal office.
(3) Rules and regulations 
The Secretary, after consultation with the Director of the Office of Personnel Management, may issue rules and regulations to provide for the enforcement of this section, which may include provisions for summary suspension of assistance or other action necessary to permit enforcement on an emergency basis.