Constitutional question?acting president run for legislative office? 
The President is temporarily incapacitated without a Vice President to
assume the Presidency.  The Speaker of the House takes the office
temporarily as acting president and resigns from the legislative
branch since it?s unconstitutional to concurrently hold offices in
multiple branches.  The Speaker?s resignation created a vacancy in the
congressional seat that he can?t simply retake upon conclusion of
executive duty.  Nor can the governor, or any other individual simply
appoint him. The position needs to be filled by election.  ?Article I,
Section 2, Clause 4: When vacancies happen in the Representation from
any State, the Executive Authority thereof shall issue Writs of
Election to fill such Vacancies.? 
http://www.house.gov/Constitution/Constitution.html.
Many officials retain their office while running for higher office,
why not the converse?
Can the individual, while acting president, run for that congressional seat AND
then hold that election in abeyance until the relinquishment of
executive powers and then
resume as a Member of Congress? Or
must the election be undertaken AFTER the relinquishment of executive power?
Probably depends on the states whether or not they will allow it on the ballot.
How would most states view this?