U.S. Senator, Barbara Boxer’s announcement that she will throw in the towel in 2016 rather than seek a 5th term comes as little surprise. Her failure to begin raising campaign funds was a sure sign that she had decided to call it quits. Although 74, she rules out age as a factor.

The diminutive Boxer’s meteoric rise from obscure Marin/Sonoma County Supervisor to the House for five terms and then on to the U.S. Senate in 1992, the so-called “Year of the Woman” when three others, including Sen. Dianne Feinstein  (who is 81) were also elected, is one of the great success stories in California politics.

As an unapologetic liberal who seemed to relish combat with many of her much more conservative seat mates, from the very beginning Boxer has always marched to her own drummer.

Former GOP Senate leader, Bob Dole, labeled her “the most partisan Senator I have ever known.”

That only partially describes the feisty Brooklyn-born college cheerleader and former stockbroker who were tutored in politics by California’s two liberal giants—state Democratic Party leader, John Burton, who she succeeded in Congress, and the legendary Rep. George Miller (D-Martinez) recently retired.

Her married name suits her well. The future Chair of the Senate Environment and Public Works Committee combined keen political savvy with theatrical flair and the quick reflexes of a street fighter to carve out a piece of California’s voter turf that she has defended successfully over 22 years compiling double-digit victories in each election.

Her first Senate skirmish was with conservative Los Angeles TV political host, Bruce Herschensohn, who she only narrowly dispatched by a razor-thin 4.9% margin after some controversial disclosures about visits he was making to strip clubs allegedly leaked by the Boxer campaign. The campaign denied complicity.

While she was thought vulnerable each time she ran because of her liberal positions, Boxer vanquished each successive GOP foe handily. These included sitting California Treasurer, Matt Fong and six years later the sitting Secretary of State, Bill Jones who she bested by 20 points.

Her final run in 2010 was a no-holds barred contest with her first female opponent, former Hewlett Packard CEO, Carly Fiorina, the energetic but ill-equipped businesswoman who proved no match for the battle-tested, veteran lawmaker. Boxer won going away by 10 percentage points.

Boxer’s penchant for dramatics especially in her early career irked many— and not just Republicans—who viewed her antics playing to the camera as more headline grabbing than serious legislating.

As a lowly House backbencher she quickly became a scourge to the Pentagon blasting wasteful military spending. One of the more famous images proudly displayed in her office depicts Boxer holding up a $7,622 coffee pot used in military cargo planes, and $600 toilet seat cover.

Using her membership on the House Armed Services Committee to good advantage, Boxer could endear herself to the anti-war constituency that propelled her into office.

However on arriving in the Senate where she was appointed to the Foreign Relations Committee Boxer was careful to moderate some of her views without alienating her base supporters.

In 2001 in the wake of 9/11 she voted against the war in Iraq but also authored legislation to protect commercial airliners against attacks by shoulder-fired missiles as well as a law calling for airline pilots to get special training to carry guns in the cockpit.

Another of the much-ballyhooed photos on her Senate wall shows her and six other female House members in 1991 charging up the Capitol steps that lead to the Senate demanding the Senate look into allegations of sexual harassment brought by Anita Hill against Supreme Court Justice, Clarence Thomas, during his confirmation hearings.

While this caused apoplexy among some members of the upper house who are typically very protective of their privacy and the chamber’s solemn (and rarely breached) tradition for maintaining decorum, it only solidified Boxer’s reputation as a fighter against injustice.

The passionate dislike she arouses in her adversaries seems only to embolden her further and the intensity of the opposition to many of her positions has served mainly to rally her supporters only the more so to her side.

However in an arena where horse trading and compromise is standard modus operandi for bridging otherwise rigid ideological divides, Boxer is not known for a willingness to “reach across the aisle” if it means abandoning goals and principles she fiercely advocates.

In comparison, Sen. Feinstein, the Bay Area’s other Senator who is by no means loathe to speak out with equal conviction, takes a more bi-partisan approach that has often produced favorable results. Interestingly the two Senators have worked well together and have co-sponsored legislation.

Nevertheless, while Boxer’s more doctrinaire work ethic endears her to her allies it can exasperate her opponents.

As one example, the long-debated cap and trade climate bill (known as the Lieberman-Warner bill) which was reported out of the  powerful Environment and Public Works Committee she has chaired did so without a single Republican vote. Some believe acceptance of a few of the more benign amendments might have improved chances for gaining support from Republican members.

With Sen. Jim Inhofe (R-Oklahoma) the new Chair and the leading proponent of the anti-climate control wing and with the GOP now in control of both Houses, all bets are now off on meaningful climate change reform during the balance of Obama’s presidency.  Nevertheless Boxer’s tireless advocacy for environmental reforms will be a lasting part of her legacy.

While she may be lacking in style points, a majority of her constituents continue to sing her praises on such issues as environmental protection, the blocking of oil drilling, abortion and women’s rights, gun control, and many more that spanned her career.

In a chamber still dominated by males (there are a record 20 women in the Senate and 84 in the House) Boxer shows little sign of letting up.

Yet her popularity in California has never waned perhaps due in part to the fact that—agree with her or not— the scrappy lady has never shied from a cause she thought worth fighting for.

Speculation is already rampant about those who might want to replace her and with Minority Leader, Nancy Pelosi (D-San Francisco), also 74 and Sen. Feinstein looking at possible retirements in the near future, a wholesale juggling of the state’s power structure is inevitable.