Federal Campaign Laws Require Donor's Occupation and Employer: Fair or Foul?

The Constitution of the United States of America guarantees Americans the right to free speech in the First Amendment of the Bill of Rights. The Founding Fathers wrote this to allow people to disagree with their government and to avoid recrimination or persecution for their opposition or support of any political beliefs.

Campaign finance laws now require Americans to list their occupation and employer when donating money to a political campaign. Laws also require publicly publishing the names of donors, the recipient and the amount. This can chill free speech because anyone can look up donations and use it to punish someone. For instance, an employer may secretly disqualify an applicant because he donated to a different political party.

The First Amendment of the Constitution: Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof; or abridging the freedom of speech, or of the press; or the right of the people peaceably to assemble, and to petition the Government for a redress of grievances.
From the Mitt Romney 2012 donation form:
"Federal law requires us to obtain and report your occupation and the name of your employer. If you are not employed, please enter None."

From the Barack Obama 2012 donation form:
"Federal law requires us to use our best efforts to collect and report the name, mailing address, occupation, and employer of individuals whose contributions exceed $200 in an election cycle."


Does requiring information about employment violate the First Amendment? Or is it a fair federal law?