A woman holds up a sign that reads"Stimulus! Audacity of Dopes"

Yes.
What does it exactly mean?

Before he became president of the USA, Barak Obama wrote a book titled "The Audacity of Hope." The sign here is a play on words, "dope" rhyming with "hope". A "dope" in this context is slang for a foolish person. The person holding the sign is unhappy with Obama's handling of the economic crisis (he introduced a financial package - a "stimulus" - designed to increase economic activity after the banking crisis of 2008).

Poor Obama. I do like him.

Thank you.