Conversation so far:
Who did Michael Bloomberg run against in the 2001 election?
In the 2001 rescheduled primary, Bloomberg defeated Herman Badillo, a former Democrat Congressman, to become the Republican nominee.
Did Michael Bloomberg win the 2001 election?
Michael Bloomberg defeated opponent Mark J. Green in a close election held just weeks after the September 11 terrorist attacks.

Question: How much did he spend on his campaign efforts?
Self-contained rewrite: How much did Michael Bloomberg spend on his campaign efforts in 2001?