Presidential hopefuls: Hidden Achilles' heels

Rick Hampson | USA TODAY

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"Every candidate may be wonderful,'' Mitt Romney said recently of the 2016 presidential field in a Fox News interview. "But they all have a but'' — a pun the 2012 GOP nominee did not need to spell out.

The candidates tell us plenty about their strengths. They're more reticent about their weaknesses (their "buts''), including the less obvious ones.

Every candidate has such an Achilles' heel, a secondary or tertiary liability that can come suddenly to light in a presidential campaign, particularly after the early primary winnowing. It can be a little-known misdeed, personality trait or biographical detail.

Example: In 1999, John McCain was far behind in the GOP presidential polls, riding the Straight Talk Express campaign bus, and charming reporters with his candor and accessibility. Few in his campaign worried about the Arizona senator's formidable temper.

But after his candidacy caught fire, McCain's "emotional balance'' suddenly and unexpectedly became an issue, recalls Dan Schnur, who was campaign communications director. "When we were at 5% (in the polls),'' he says, "we didn't worry about it.''

"Smart campaigns understand their candidates' weaknesses at an intellectual level,'' says Schnur, now director of USC's Unruh Institute of Politics. "But it's hard to process them viscerally. You believe in your candidate, and you're surrounded by others who believe.''

Such weaknesses are often hidden in plain sight or obscured by more glaring ones — such as Bridgegate (Chris Christie) or "Oops!" (Rick Perry). Apparent to insiders and cognoscenti, they can be unseen by the average voter, because the election is so far away and the candidates (currently five Democrats, 15 Republicans) are so many.

And sometimes a weakness might be a strength. Is Scott Walker's lack of a college degree a liability or a badge of honor? If Ted Cruz is unpopular with his congressional colleagues, who as a group are unpopular with the public, is that a plus?

Here's a list of some of the presidential candidates and their possible weaknesses — obvious and not so obvious:

JEB BUSH

Obvious weakness: Voter fatigue with family name and disapproval of war prosecuted by brother

Other weakness: Terri Schiavo case

As Florida governor, Bush went to extraordinary lengths to oppose efforts by Schiavo's husband, Michael, to have her disconnected from life support. Terri had suffered massive brain damage after a heart attack in 1990; eight years later, Michael asked a court to remove her feeding tube, citing medical testimony that she was in a vegetative state. Terri's parents challenged the diagnosis and opposed the removal. After massive legal and political wrangling, the tube was removed and Terri died in March 2005.

Now Michael Schiavo says he'll campaign against Bush and remind voters about his role in the case. Schiavo told the Associated Press earlier this year that Bush "owes the public, along with myself, a huge apology." Asked about the case by the Tampa Bay Times, Bush said: "It's appropriate for people to err on the side of life.''

Ken Wald, a University of Florida political scientist, says the case revealed Bush as a stubborn governor who "always believed he was right and was willing to alienate moderates in his own party.''

HILLARY CLINTON

Obvious weakness: Trustworthiness, as measured by polls

Other weakness: Post-primary pivot

All candidates adjust their message as they move from primaries to general elections. But the former secretary of State, whose Democratic challengers — including an avowed socialist — are to her left, might find the pivot more wrenching than most. And, unlike her husband, she's not the supplest of politicians to begin with.

Unfortunately for Clinton, her fellow Democrats may not sympathize. In a CNN/ORC poll released last month, 53% said a competitive primary race would be best for the party.

SCOTT WALKER

Obvious weakness: Inexperience in foreign affairs

Other weakness: College dropout

Walker left Marquette in his senior year to take a job, and the Wisconsin governor still is more than 30 credits shy of his bachelor's degree. Dropout status might be a plus (see Bill Gates, Mark Zuckerberg, etc.), but Walker's advisers want him to come across as smart, and if he wins the nomination he could face the heavily credentialed Clinton (Wellesley '69, Yale Law '73, Yale School of Medicine fellowship '74).

MARCO RUBIO

Obvious weakness: 2013 immigration bill, which he initially co-sponsored and later opposed

Other weakness: Bridesmaid

A lot of Republican voters like Marco Rubio; not enough love him. He's a popular second choice. That's partly because he commands no particular constituency: He shares Florida with Bush, Hispanic heritage with Ted Cruz, evangelical Christianity with Mike Huckabee and Walker. And, as someone pointed while Rubio was on the campaign trail in Iowa, he's another young, articulate, first-term, minority-group U.S. senator — like a Democrat who ran in 2008.

RAND PAUL

Obvious weakness: Isolationist foreign policy tendencies

Other weakness: Potentially embarrassing dad

Former congressman Ron Paul is a maverick. That's great when you're the maverick (and not terribly concerned about higher office), and not so great when you're the son to whom reporters will rush when the maverick says something controversial. In the past, Ron has advocated legalizing heroin and said NSA leaker Edward Snowden rendered a "great service to the American people by exposing the truth about what our government is doing in secret."

Schnur: "If you thought it was hard to watch Jeb Bush try to separate himself from his brother, wait until Rand Paul has to disavow something his father says.''

The acorn didn't fall far from the tree. Rand, says University of Kentucky political analyst Stephen Voss, tends "to go off-script and dig holes for himself.'' After he won the GOP U.S. Senate primary in 2010, he sparked a distracting controversy by musing that the Civil Rights Act of 1964 infringed on the rights of private businesses.

CHRIS CHRISTIE

Obvious weakness: Bridgegate

Other weakness: Atlantic City

Given the inevitable fall of its casino gambling monopoly, Atlantic City might have seemed a risky political entanglement in 2011 for a man with presidential aspirations. But the New Jersey governor tied his then-rising star to this political millstone. He created a special tourism district; appeared repeatedly to cut ribbons and give pep talks; and backed emergency state tax credits for Revel, a 70-story hotel-casino that he called "the model for the future."

Now Revel and three other casinos are closed, thousands of employees are jobless and the city's finances are in ruins.

And now Christie owns the problem; any opponent with a video camera will find scenes along the Boardwalk far more graphic than those of Boston Harbor pollution that helped sink Democratic nominee (and Massachusetts governor) Michael Dukakis in 1988.

BERNIE SANDERS

Obvious weakness: Obama's enemies claim he's a socialist; Sanders is one

Other weakness: Gun control

Sanders is very liberal on most issues, but not guns. In 1993, while serving in the House, he voted against the Brady Bill, which created mandatory background checks for gun buyers. He said the matter was best left to the states. In 2005 Sanders voted for an NRA-backed bill to protect gun makers and dealers from negligence suits by gun crime victims.

But Sanders also voted for a ban on assault weapons and for a measure, introduced after the Newtown massacre in 2012, to expand background checks and close the gun show sales loophole.

DONALD TRUMP

Obvious weakness: Remarks about Mexican immigrants — as well as prominent members of the party he hopes will nominate him, including John McCain, Mitt Romney, George W. Bush, Dick Cheney, Karl Rove, Ronald Reagan, etc.

Other weakness: Hates to shake hands

From Trump: The Art of the Comeback (1997): "I happen to be a clean-hands freak. I feel much better after I thoroughly wash my hands, which I do as often as possible."

Trump wrote that he hates being approached in a restaurant by someone en route from the men's room, "perhaps not even having washed his hands. … If you shake his hand, you then get up to rewash your hands, and inevitably somebody else comes over to you to shake hands. If you don't shake his hand, he walks away with a long face, totally insulted.''

As Ford O'Connell, a strategist who worked on the 2008 McCain/Palin campaign, notes: "It's got to be a challenge for him to go around barnstorming and kissing babies.''

TED CRUZ

Obvious weakness: Widely despised by Senate colleagues such as McCain, who called Cruz and Rand Paul right-wing "wacko birds''

Other weakness: Trump

In the '16 field, says O'Connell, "Cruz was the fighter who didn't parse his words. Now there's Trump, eating up all the oxygen in that room.''

Follow @rickhampson on Twitter.

Contributing: Ledyard King