Hillary Clinton has been tapped to replace former President George W. Bush as the featured speaker at the Ameriprise Financial conference in Boston next week, according to the Web site Politico.com.

Bush was anticipated to be the main attraction at the event, but he is reported to be recovering from knee surgery and is unable to attend.

It is common practice for Beltway heavyweights to pinch-hit for each other in the event of emergencies. At last year's Pershing conference, former Secretary of Defense Robert Gates filled in for Secretary Clinton after she decided to cancel her appearance so she could attend the funeral of former New Jersey Sen. Frank Lautenberg.

Clinton, the former secretary of state and a likely 2016 presidential contender, charges upward of $200,000 to deliver remarks or take part in question-and-answer sessions. In recent weeks, she has been criticized by members of the Democratic Party's left wing for her close relationship with Wall Street and for giving several speeches at events sponsored by Goldman Sachs.

Others have questioned whether it is appropriate for Clinton in particular and other politicians in general to accept six-figure fees from universities that are hitting debt-strapped students with hefty tuition hikes. Clinton herself has donated many of her fees to The Clinton Foundation. But critics note that during the recession in 2001 former President Bill Clinton waived his fee to speak at the State University Of New York in Buffalo. At that time, the Clintons were not nearly as wealthy as they are today.

Bush charges about $110,000 per address, according to Yahoo!News. Other published reports have the former president earning as much as $150,000 per speech.

Neither former Secretary of State Clinton nor former President Bush has earned as much money on the speaking circuit as former President Clinton. Since leaving office in 2001, former President Clinton has earned at least $106 million to do what he enjoys most, namely to talk, according to CNN and other sources.

The precise date of Hillary Clinton's speech isn’t immediately clear, but the conference runs from July 23 to 27.