WASHINGTON - Supporters of former U.S. Secretary of State Hillary Clinton were offended this week when a prominent Republican strategist questioned her health amid mounting speculation that Clinton will run for president in 2016. This could be an early preview of the 2016 presidential campaign from Washington.

The New York Post Iran a headline with the words “brain damage” in reporting on comments from Republican strategist Karl Rove during a recent speech that raised questions about Hillary Clinton’s health.

Clinton did not address the Rove comments in a speech Friday.

She was treated for a blood clot in 2012 after suffering a concussion in a fall at her home.

Former President Bill Clinton laughed off Rove’s comments and said his wife is in good health. “Now they say she has really got brain damage. If she does, then I must be in really tough shape because she is still quicker than I am.”

Rove was a key political adviser to former President George W. Bush and sought to clarify his remarks on Fox News. “I didn’t say she had brain damage. She had a serious health episode. This will be an issue in the 2016 race whether she likes it or not,” he said.

Clinton has said she will decide on a presidential run by the end of this year.

Democratic pollster Celinda Lake said she can expect more attacks if she decides to seek the White House. “Just as people were unbounded in their commentary about Obama, they will be unbounded in their commentary on her, and she’s tough enough, she can take it.  She’s taken it for years.”

Clinton’s record as secretary of state will get fresh scrutiny from a special committee set up by House Republicans to probe the 2012 terrorist attack on the U.S. mission in Benghazi, Libya, which resulted in the deaths of four Americans.

Clinton defended her handling of the incident during a Senate hearing in 2013. “Was it because of a protest or was it because guys were out for a walk one night and decided to go kill some Americans? What difference at this point does it make?”

Clinton is familiar with Republican attacks from her eight years as first lady, said public opinion expert Karlyn Bowman.

“There is a base of opposition to Hillary Clinton.  It is part of the Republican conservative base, and that is not inconsequential, but I think she looks like a pretty strong candidate at this point,” said Bowman.

Clinton’s book on her tenure as secretary of state, entitled Hard Choices, will be published next month.