The 121st Boston Marathon may be in the record books, but the starting gun for another grueling race just went off in Massachusetts: U.S. Sen. Elizabeth Warren’s 2020 bid for the White House.

Sure, Warren denies it. But like Hillary Clinton before her, she is using the release of her latest book — her 11th for those keeping score — to wade into the presidential waters.

A politician’s book tour usually consists of media interviews and promotional events across the country, and Warren is following that playbook. She kicked things off not in Massachusetts, the state she is supposed to represent, but in New York City, home to an abundance of potential donors and media outlets.

Amazingly, Warren bungled one of the first questions out of the gate, failing to deliver a smooth response on NBC’s “Today Show” to the predictable query about her presidential ambitions. “Warren dodges on whether she’ll run for president in 2020” blared the headline from Politico.

Instead of a round of positive stories about her book, Warren faced an onslaught of headlines about her political ambitions. The situation was reminiscent of Clinton’s debut interview during her 2014 book tour when the former secretary of state described herself as “dead broke.” Clinton spent the ensuing days trying to explain how a family whose worth has been estimated as high as $110 million was close to the breadline.

The entire fiasco reinforced voters’ suspicions that Clinton was out of touch after 25 years in the spotlight, a narrative that remained with her for the duration of her losing campaign.

But Clinton isn’t the only former failed Democratic standard-bearer to whom Warren has drawn unfavorable comparisons in recent weeks. With North Korea and Syria dominating the headlines, debates over foreign policy are taking center stage.

As a Harvard professor and corporate attorney, Warren has long been shy of national security credentials. During her 2012 Senate campaign against Scott Brown (for whom I served as communications director), issues of war and peace took a back seat to domestic debates. That’s why Warren’s appointment to the Senate Armed Services Committee in December was widely viewed as an attempt to bolster her foreign policy resume.

Since then, Warren has staked out decidedly weak positions in an increasingly dangerous world. When President Trump launched 59 Tomahawk missiles at Syria after Bashar Assad used chemical weapons on his own people, Warren took to Twitter to declare, “no compelling strategic justification” for the action.

The stomach-churning images of children gasping for air and foaming at the mouth might not have convinced Warren action was needed, but the strike had the backing of another liberal Democrat from Massachusetts. John Kerry, who as President Obama’s secretary of state knows all about Assad’s atrocities, was “absolutely supportive” of Trump’s actions.

Warren has placed herself to the left of the flip-flopping Kerry, who lost his 2004 White House bid largely because he couldn’t convince the American public that he would be a steady wartime commander in chief.

Similarly, Warren’s skepticism toward the “mother of all bombs” that killed at least 94 ISIS fighters shows her interest lies more in politics than sound policy.

But Warren may have a 2018 problem on her hands. Recent polling data shows her shtick is not wearing well with her actual constituents. A WBUR survey from Central Massachusetts shows Warren hemorrhaging support among independents, the critical Bay State voting bloc. Only 33 percent of unenrolled voters in those towns approve of their senior senator, numbers that pale in comparison to those of Gov. Charlie Baker, who has the support of 63 percent of independents and 71 percent of Democrats.

Warren is learning the hard way that what pleases left-wing activists in Berkeley, Calif., doesn’t always fly in places like Barnstable or Braintree. Most Massachusetts voters prefer middle-of-the-road common sense over extremist ideology.

It’s the difficult balancing act Warren faces over the next 18 months as she runs for two offices simultaneously. It’s a high wire walk that has tripped up many a seasoned politician. So far, Warren’s not off to a good start.

Colin Reed is the executive director of America Rising, a Republican communications Super PAC. Follow him on Twitter @colintreed.