Watch CNN's Iowa Town Hall with the Democratic presidential candidates at 9 p.m. ET Monday. Alex Castellanos, a Republican strategist, is the founder of Purple Strategies and NewRepublican.org . Follow him on Twitter @alexcast . The opinions expressed in this commentary are his.

An untidy, 74-year-old socialist from Vermont should never have been able to climb into the ring with the former first lady, our 67th secretary of state and co-owner of one America's most loved political brands. At least in the early rounds, however, Bernie Sanders has pinned Clinton to the ropes, pummeling her with solid left hands.

The biggest contributor to Sanders' success is neither the small-dollar donor who sustains him nor the millennials who flock to his rallies. The co-author of Sanders' accomplishment is Hillary Clinton. Sen. Sanders' indispensable assistant has been the candidate he's running against.

I've only met Clinton once. She was fun and warm and rendered a few minutes a delightful experience. The public persona she has created is of a different character, a woman who has fought, not for people, but for survival and power.

The political Clinton is regarded as a strong, chilly, no-nonsense contender, not a passionate warrior for causes beyond her self-interest. Voters understand that what Clinton has endured has toughened her. If she had shown weakness or surrendered to emotion on her journey, it is doubtful she'd be where she is today.

Clinton is as much a member of the establishment as anyone in the Democratic Party. In a debate, she described one of her signal achievements: "I represented Wall Street as the senator from New York." With her party in hot revolt against the status quo, neither her frosty pragmatism nor establishment credentials endear her to the Democratic base.

Her party moved left

Hillary Clinton's Democratic Party is far left of the one her husband, Bill Clinton, fashioned when he said: "the era of big government is over."

Hillary Clinton's party has been radicalized by Internet activism. Social media has not only concentrated the Democratic Party on its left, it has also squared its intensity, much like talk-radio flamed fires on the Republican right. Success on Twitter is not earned by the moderate or the meek.

Today's Democratic Party has little room for old-school, mechanical pragmatists such as Clinton. Its heart belongs to the rebellious, agitators such as Elizabeth Warren. Combine George McGovern's 1960 anti-war protest campaign with a dash of the "Decade of Love." Tailor the mix with a sprinkle of 2016; iPhones, principled shoes ( TOMS , "The Shoes That Educate Poor People!") and replace LSD with a few pharmacological mood-stabilizers to round life's sharp edges. There, you have Bernie Sanders' throwback-to-the-future campaign: It is fantasy camp for middle-class, wannabe '60s radicals. It is an undemanding revolution, accessible without risk or effort. They would be more comfortable Ubering to Wall Street than marching on it, but their mission of insurrection is unchanged.

Before Sanders is done, Democrats may again wear bell-bottoms with peace-sign patches. Gallup reports that 59% of Democrats have no problem embracing a self-described socialist for president.

More comfortable with process than people

Perhaps no campaign comes naturally to Hillary Clinton. She is more comfortable with process than with people. But this particular crusade, requiring her to overthrow the very establishment to which she belongs and to undermine the rich, among whom she must be counted, has been uniquely difficult for her.

Clinton has campaigned with awkward artificiality. She has advocated her party's new lefty-populism with the grace of Charles Barkley's golf swing.

She has tried. She broke with President Barack Obama on the Trans-Pacific Free-Trade Deal. She cloned Sanders' support of the $15 an hour federal minimum wage. With robotic focus, Clinton even pretended to be Elizabeth Warren. When she said, "Don't let anybody tell you that... businesses create jobs," she looked like a right-handed NFL quarterback attempting a left-handed completion. Clinton is no more comfortable as candidate of the little guy than Richard Nixon walking on the beach in wing tips.

Still, the Democratic Party did not cover its ears. It tried to teach its discordant candidate to sing harmony.

At the beginning of the campaign, Democrats had accepted that Clinton offered the best shot at winning a general election and protecting the White House from a somewhat deranged mob of Republicans.

And Democrats owed a debt to Clinton: Eight years ago, they chose to correct injustices of race before those of gender. They nominated the first black president instead of the first female president. Democrats sent Hillary Clinton and the women of America to the back of the bus to wait their turn. They hoped not to do that again.

Then, Bernie Sanders gave Democrats an opportunity to party like it's 1967. They could dig their tie-dyed shirts out of the closet while helping Clinton. They could bring her home to their middle-class version of Woodstock, this time with cozy theater seating and no mud. By embracing Sanders, they could pressure Clinton to move left: At last, she would be like them.

Making Sanders into a serious rival

Initially, Sanders was not Clinton's opponent. He was a plea from concerned friends, imploring Clinton to renew herself as Hillary Rodham, Wellesley grad, and restore her radicalism.

But Clinton achieved the impossible. She transformed Bernie Sanders from an unelectable messenger to serious opponent. Again, the Sidam Touch doomed her.

Instead of letting the base of her party send her a message, Clinton attacked their messenger. While Sanders runs ads with a 1968 Simon & Garfunkel anthem, inspiring Democrats to "all come to look for America," Clinton has fought back angrily. Her campaign has called Sanders a "socialist," a move of questionable effect, in that he has proudly admitted the same.

Clinton is running Richard Nixon's campaign against the Democratic left at the same time she is appealing to it. She is trying to murder the '60s.

For the past month, Clinton has thought she has been attacking her opponent. She has actually been condemning the Democratic Party's base as it has been trying to rescue her. Instead of telling them, "I hear you!" she has informed them, "I don't get it." Her attacks have worked in reverse, expanding Sanders' advantage day by day.

In the first two states, Clinton has run out of time. The most powerful thing Democratic caucus and primary voters can do with their ballots is not consent to Clinton's rejection of their heartfelt, '60s interpretation of populism but to send her a louder message: Defeats in both Iowa and New Hampshire.

When the nomination process heads south and west after New Hampshire and the population of black and brown voters grows, Clinton's fortunes may improve -- if she is capable of finding her inner radical and applying her strength where Democrats value it, striking at Republicans instead of her base. "The enemy of my enemy," she should remember, "is my friend."

Genuine poll-tested, fake-sincere authenticity, however, is not Clinton's gift. Communing with the little people may not be in her.

In politics, tides usually rise and fall to their previous marks. The tide has gone out on Clinton before. It could easily do so again.

Poor Hillary Clinton has the Sadim Touch. Everything she taps turns to lead.