This is a bad idea on just too many levels:
Office of Management and Budget Employees to Push to Unionize - Political Punch
Asked for comment, Kenneth Baer, OMB communications director, told ABC News that the Obama administration “is a strong supporter of the right of workers to organize. It is up to the people working at any bargaining unit to decide if they want to join a union or not. Whatever the decision of these employees may be, we are committed to working together to serve the President and the American people.”
Public sector unions are unlike unions in private industry. Union employees would be analyzing federal expenditures, which often involve unionized employees. The potential conflicts are numerous. Federal unions donate to political campaigns, electing the very men and women the unions then "bargain" with -- not a good system. At the turn of the last century, New York state had to limit the power of New York City politicians because union bosses and politicians had created a patronage system.
We're building a new, equally foul, patronage system. Don't pretend politicians supported by unions won't try to cater to those same unions.
Federal civil service law offers numerous protections most union contracts don't guarantee. What issues are leading the increased move to unionize federal workers? Normal competitive pressures do not exist in government.
I'm a member of two unions and will probably join a third within the next few years. But, these unions negotiate in private, competitive industries. Also, I'm not in a standard step-and-ladder compensation system: I am paid based on the demand for my work.