Story highlights Karl Rove suggested that Hillary Clinton suffers from a brain injury

Rove has come under fire for his comments

Clinton suffered a blood clot in December 2012 after falling

Bill Clinton says Hillary is strong, and is "in better shape than I am"

Karl Rove's suggestion that Hillary Clinton suffers from a brain injury prompted Democrats to come to her defense. And now, her husband is speaking up, saying "she's strong and working out."

Rove, the mastermind behind George W. Bush's two presidential election victories, appeared at a conference last week, where he discussed a 2012 incident that sent the then-secretary of state to the hospital, according to the New York Post's Page Six gossip column.

"Thirty days in the hospital?" asked Rove, a Fox News Channel contributor, according to the report. "And when she reappears, she's wearing glasses that are only for people who have traumatic brain injury? We need to know what's up with that."

Clinton, who's seriously considering a second bid for the White House, suffered a blood clot in December 2012, after falling. After first going to the hospital for testing, Clinton later was admitted for a three-day stay at a hospital in New York.

The incident prevented her from testifying before Congress about the deadly 2012 terror attack on the American diplomatic compound in Benghazi, Libya, raising questions from some Republicans. She eventually appeared before lawmakers in January 2013.

Photos: Hillary Clinton's life in the spotlight Photos: Hillary Clinton's life in the spotlight Hillary Clinton accepts the Democratic Party's nomination for president at the Democratic National Convention in Philadelphia on July 28, 2016. The former first lady, U.S. senator and secretary of state was the first woman to lead the presidential ticket of a major political party. Hide Caption 1 of 43 Photos: Hillary Clinton's life in the spotlight Before marrying Bill Clinton, she was Hillary Rodham. Here she attends Wellesley College in Massachusetts. Her commencement speech at Wellesley's graduation ceremony in 1969 attracted national attention. After graduating, she attended Yale Law School. Hide Caption 2 of 43 Photos: Hillary Clinton's life in the spotlight Rodham was a lawyer on the House Judiciary Committee, whose work led to impeachment charges against President Richard Nixon in 1974. Hide Caption 3 of 43 Photos: Hillary Clinton's life in the spotlight In 1975, Rodham married Bill Clinton, whom she met at Yale Law School. He became the governor of Arkansas in 1978. In 1980, the couple had a daughter, Chelsea. Hide Caption 4 of 43 Photos: Hillary Clinton's life in the spotlight Arkansas' first lady, now using the name Hillary Rodham Clinton, wears her inaugural ball gown in 1985. Hide Caption 5 of 43 Photos: Hillary Clinton's life in the spotlight The Clintons celebrate Bill's inauguration in Little Rock, Arkansas, in 1991. He was governor from 1983 to 1992, when he was elected President. Hide Caption 6 of 43 Photos: Hillary Clinton's life in the spotlight Bill Clinton comforts his wife on the set of "60 Minutes" after a stage light broke loose from the ceiling and knocked her down in January 1992. Hide Caption 7 of 43 Photos: Hillary Clinton's life in the spotlight In June 1992, Clinton uses a sewing machine designed to eliminate back and wrist strain. She had just given a speech at a convention of the International Ladies' Garment Workers Union. Hide Caption 8 of 43 Photos: Hillary Clinton's life in the spotlight During the 1992 presidential campaign, Clinton jokes with her husband's running mate, Al Gore, and Gore's wife, Tipper, aboard a campaign bus. Hide Caption 9 of 43 Photos: Hillary Clinton's life in the spotlight Clinton accompanies her husband as he takes the oath of office in January 1993. Hide Caption 10 of 43 Photos: Hillary Clinton's life in the spotlight The Clintons share a laugh on Capitol Hill in 1993. Hide Caption 11 of 43 Photos: Hillary Clinton's life in the spotlight Clinton unveils the renovated Blue Room of the White House in 1995. Hide Caption 12 of 43 Photos: Hillary Clinton's life in the spotlight Clinton waves to the media in January 1996 as she arrives for an appearance before a grand jury in Washington. The first lady was subpoenaed to testify as a witness in the investigation of the Whitewater land deal in Arkansas. The Clintons' business investment was investigated, but ultimately they were cleared of any wrongdoing. Hide Caption 13 of 43 Photos: Hillary Clinton's life in the spotlight The Clintons hug as Bill is sworn in for a second term as President. Hide Caption 14 of 43 Photos: Hillary Clinton's life in the spotlight The first lady holds up a Grammy Award, which she won for her audiobook "It Takes a Village" in 1997. Hide Caption 15 of 43 Photos: Hillary Clinton's life in the spotlight The Clintons dance on a beach in the U.S. Virgin Islands in January 1998. Later that month, Bill Clinton was accused of having a sexual relationship with former White House intern Monica Lewinsky. Hide Caption 16 of 43 Photos: Hillary Clinton's life in the spotlight Clinton looks on as her husband discusses the Monica Lewinsky scandal in the Roosevelt Room of the White House on January 26, 1998. Clinton declared, "I did not have sexual relations with that woman." In August of that year, Clinton testified before a grand jury and admitted to having "inappropriate intimate contact" with Lewinsky, but he said it did not constitute sexual relations because they had not had intercourse. He was impeached in December on charges of perjury and obstruction of justice. Hide Caption 17 of 43 Photos: Hillary Clinton's life in the spotlight The first family walks with their dog, Buddy, as they leave the White House for a vacation in August 1998. Hide Caption 18 of 43 Photos: Hillary Clinton's life in the spotlight President Clinton makes a statement at the White House in December 1998, thanking members of Congress who voted against his impeachment. The Senate trial ended with an acquittal in February 1999. Hide Caption 19 of 43 Photos: Hillary Clinton's life in the spotlight Clinton announces in February 2000 that she will seek the U.S. Senate seat in New York. She was elected later that year. Hide Caption 20 of 43 Photos: Hillary Clinton's life in the spotlight Clinton makes her first appearance on the Senate Environment and Natural Resources Committee. Hide Caption 21 of 43 Photos: Hillary Clinton's life in the spotlight Sen. Clinton comforts Maren Sarkarat, a woman who lost her husband in the September 11 terrorist attacks, during a ground-zero memorial in October 2001. Hide Caption 22 of 43 Photos: Hillary Clinton's life in the spotlight Clinton holds up her book "Living History" before a signing in Auburn Hills, Michigan, in 2003. Hide Caption 23 of 43 Photos: Hillary Clinton's life in the spotlight Clinton and another presidential hopeful, U.S. Sen. Barack Obama, applaud at the start of a Democratic debate in 2007. Hide Caption 24 of 43 Photos: Hillary Clinton's life in the spotlight Obama and Clinton talk on the plane on their way to a rally in Unity, New Hampshire, in June 2008. She had recently ended her presidential campaign and endorsed Obama. Hide Caption 25 of 43 Photos: Hillary Clinton's life in the spotlight Obama is flanked by Clinton and Vice President-elect Joe Biden at a news conference in Chicago in December 2008. He had designated Clinton to be his secretary of state. Hide Caption 26 of 43 Photos: Hillary Clinton's life in the spotlight Clinton, as secretary of state, greets Russian Prime Minister Vladimir Putin during a meeting just outside Moscow in March 2010. Hide Caption 27 of 43 Photos: Hillary Clinton's life in the spotlight The Clintons pose on the day of Chelsea's wedding to Marc Mezvinsky in July 2010. Hide Caption 28 of 43 Photos: Hillary Clinton's life in the spotlight In this photo provided by the White House, Obama, Clinton, Biden and other members of the national security team receive an update on the mission against Osama bin Laden in May 2011. Hide Caption 29 of 43 Photos: Hillary Clinton's life in the spotlight Clinton checks her Blackberry inside a military plane after leaving Malta in October 2011. In 2015, The New York Times reported that Clinton exclusively used a personal email account during her time as secretary of state. The account, fed through its own server, raises security and preservation concerns. Clinton later said she used a private domain out of "convenience," but admits in retrospect "it would have been better" to use multiple emails. Hide Caption 30 of 43 Photos: Hillary Clinton's life in the spotlight Clinton arrives for a group photo before a forum with the Gulf Cooperation Council in March 2012. The forum was held in Riyadh, Saudi Arabia. Hide Caption 31 of 43 Photos: Hillary Clinton's life in the spotlight Obama and Clinton bow during the transfer-of-remains ceremony marking the return of four Americans, including U.S. Ambassador Christopher Stevens, who were killed in Benghazi, Libya, in September 2012. Hide Caption 32 of 43 Photos: Hillary Clinton's life in the spotlight Clinton ducks after a woman threw a shoe at her while she was delivering remarks at a recycling trade conference in Las Vegas in 2014. Hide Caption 33 of 43 Photos: Hillary Clinton's life in the spotlight Clinton, now running for President again, performs with Jimmy Fallon during a "Tonight Show" skit in September 2015. Hide Caption 34 of 43 Photos: Hillary Clinton's life in the spotlight Clinton testifies about the Benghazi attack during a House committee meeting in October 2015. "I would imagine I have thought more about what happened than all of you put together," she said during the 11-hour hearing. "I have lost more sleep than all of you put together. I have been wracking my brain about what more could have been done or should have been done." Months earlier, Clinton had acknowledged a "systemic breakdown" as cited by an Accountability Review Board, and she said that her department was taking additional steps to increase security at U.S. diplomatic facilities. Hide Caption 35 of 43 Photos: Hillary Clinton's life in the spotlight U.S. Sen. Bernie Sanders shares a lighthearted moment with Clinton during a Democratic presidential debate in October 2015. It came after Sanders gave his take on the Clinton email scandal. "The American people are sick and tired of hearing about the damn emails," Sanders said. "Enough of the emails. Let's talk about the real issues facing the United States of America." Hide Caption 36 of 43 Photos: Hillary Clinton's life in the spotlight Clinton is reflected in a teleprompter during a campaign rally in Alexandria, Virginia, in October 2015. Hide Caption 37 of 43 Photos: Hillary Clinton's life in the spotlight Clinton walks on her stage with her family after winning the New York primary in April. Hide Caption 38 of 43 Photos: Hillary Clinton's life in the spotlight After Clinton became the Democratic Party's presumptive nominee, this photo was posted to her official Twitter account. "To every little girl who dreams big: Yes, you can be anything you want -- even president," Clinton said. "Tonight is for you." Hide Caption 39 of 43 Photos: Hillary Clinton's life in the spotlight Obama hugs Clinton after he gave a speech at the Democratic National Convention in Philadelphia. The president said Clinton was ready to be commander in chief. "For four years, I had a front-row seat to her intelligence, her judgment and her discipline," he said, referring to her stint as his secretary of state. Hide Caption 40 of 43 Photos: Hillary Clinton's life in the spotlight Clinton arrives at a 9/11 commemoration ceremony in New York on September 11. Clinton, who was diagnosed with pneumonia two days before, left early after feeling ill. A video appeared to show her stumble as Secret Service agents helped her into a van. Hide Caption 41 of 43 Photos: Hillary Clinton's life in the spotlight Clinton addresses a campaign rally in Cleveland on November 6, two days before Election Day. She went on to lose Ohio -- and the election -- to her Republican opponent, Donald Trump. Hide Caption 42 of 43 Photos: Hillary Clinton's life in the spotlight After conceding the presidency to Trump in a phone call earlier, Clinton addresses supporters and campaign workers in New York on Wednesday, November 9. Her defeat marked a stunning end to a campaign that appeared poised to make her the first woman elected US president. Hide Caption 43 of 43

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Should Clinton, 66, decide to seek the presidency, her health likely would be raised in the same context as any other candidate.

Democrats and others were quick to slam Rove. The Democratic National Committee put out a statement saying, "It appears Karl Rove's medical diagnoses are about as solid as his election night prognostications."

The statement refers to Rove's prediction that Mitt Romney would win the 2012 presidential election.

Clinton spokesman Nick Merrill said "Karl Rove has deceived the country for years, but there are no words for this level of lying."

As for Clinton's health, Merrill added, "She is 100%. Period."

Former president weighs in

On Wednesday, former President Bill Clinton said he was "sort of dumbfounded" by the comments.

"Look, she works out every week, she is strong, she's doing great. As far as I can tell she's in better shape than I am. She certainly seems to have more stamina now," he said.

Clinton also joked about Rove.

"I got to give him credit, you know, that embodies that old saying that consistency is the hobgoblin of little minds. First they said she faked her concussion. And now they say she's auditioning for a part on the Walking Dead," he said.

Rove defended his comments on Tuesday on Fox News Channel, saying that it's legitimate to ask about a potential presidential candidate's health.

"No, no. I didn't say she had brain damage, she had a serious health episode and my point was that I think it was from the 7th of December in 2012 through the 7th of January of 2013, she underwent, first she had apparently a serious virus.

"They announced then on the 15th of December that she had at some period in the past week fallen. They didn't say when, they didn't say where. She was recovering at home. On the 30th of December she goes in and turns out to have had a blood clot. They won't say where.

"The next day they say it is between her skull and her brain behind her right ear. She is in the hospital for four days. She goes home, is back in the office on the 7th and testifies on the 25th wearing special glasses that allow her to deal with the double vision that this episode caused," Rove said

While she was hospitalized, Clinton's doctors said they were confident that she would make a full recovery.

Clinton has increasingly come under attack by Republicans as she seriously considers a presidential bid. If she decides to run, she would instantly become the overwhelming frontrunner for the Democratic nomination. At the same time, Clinton is keeping up a very demanding speaking schedule that includes lots of travel.

Stepped up attacks

While she mulls her decision, the GOP and pro-Republican outside groups have stepped up their attacks on Clinton, on everything from the Benghazi incident to the 1990s Monica Lewinsky scandal.

Rove said Clinton's health will be a factor if she runs.

"My point was that Hillary Clinton wants to run for president, but she would not be human if this didn't enter in as a consideration. My other point is this will be an issue in the 2016 race whether she likes it or not. Every presidential candidate is asked for their health records," Rove added Tuesday.

Following Rove's appearance on Fox News, Merrill released a new statement.

"From the moment this happened 17 months ago, the Right has politicized her health. First they accused her of faking it, now they've resorted to the other extreme -- and are flat out lying. Even this morning, Karl Rove is still all over the map and is continuing to get the facts wrong. But he doesn't care, because all he wants to do is inject the issue into the echo chamber, and he's succeeding. It's flagrant and thinly veiled," Merrill said.

The 2012 incident was not the first time Clinton dealt with blood clots.

She told the New York Daily News in 2007 that while campaigning for Sen. Chuck Schumer in 1998 she suffered a large blood clot behind her right knee and had to be rushed to Bethesda Naval Hospital.

Clinton also fell and fractured her right elbow as secretary of state in 2009 and was treated at George Washington University Hospital.

Age an issue in presidential elections

Rove pointed out that some Democrats in 2008 made Republican presidential nominee John McCain's age an issue during the campaign. The age attacks were not limited to outside groups, either. Then-Sen. Barack Obama said McCain had "lost his bearings" while pursuing the Republican nomination, a line that was seen as a subtle attack.

Age is often made a campaign issue. Bill Clinton's campaign portrayed incumbent George H.W. Bush as old and out of touch during the 1992 presidential race.

Then-President Ronald Reagan famously turned the issue on its head in 1984 by telling voters during a debate with challenger Walter Mondale that "I am not going to exploit, for political purposes, my opponent's youth and inexperience."