Sen. Elizabeth Warren (D-Mass.) made some news Wednesday when she declared, "I am not running for president and I plan to serve out my term."

That should surprise no one.

While the freshman senator has been the subject of a lot of presidential chatter of late -- including on this blog, where she has been a regular feature on our rundown of potential 2016 candidates -- most of it has been externally driven. For her part, Warren has done little to encourage such talk. In fact, she's kept a deliberately low profile.

Warren doesn't seek out the media attention that other rising stars in the Senate like Rand Paul (R-Ky.), Ted Cruz (R-Tex.) and Marco Rubio (R-Fla.) go after. She doesn't make regular rounds on the Sunday shows or make much news with off-the-cuff comments in the halls of the Capitol 0r remarks on the Senate floor. As the Boston Globe reported earlier this year, she has kept her head down on purpose during her brief tenure on Capitol Hill.

Yet, she has become the subject of great speculation and fascination when it comes to 2016. Warren was the focus of a recent New Republic magazine cover story titled "Hillary's Nightmare."

It's not difficult to see why. Warren is a dyed-in-the-wool liberal who has championed economic equality, taken on the banking industry (she was the architect of the Consumer Financial Protection Bureau) and made the case for expanding Social Security benefits when even President Obama has backed the idea of reducing the program.

Just as important, she has proven to be a very capable politician, raising eye-popping sums of money in her campaign to unseat Republican Scott Brown last year and staying diligently on message against the skilled retail politician. She can also deliver a stemwinder, as evidenced by the rousing reception she received at this year's AFL-CIO convention.

That combination is very rare in today's Democratic Party. So rare that no one really occupies the space Warren does. That's why she is so appealing to the liberal base.

What's more, Warren's arrival on the national political scene comes amid an emerging populist movement in the party that she neatly embodies. Former secretary of state Hillary Clinton, viewed widely as the frontrunner for the 2016 Democratic nomination if she runs for president, has never been a darling of the political left. But Warren fits that bill nicely.

To be clear though, none of that means Warren was ever seriously pondering a run. In addition to her eschewing the spotlight, there is the presence of Clinton, who, unlike Warren, has shown signs that she is gearing up for a 2016 bid.

It would be difficult to envision Warren challenging Clinton, who has won the admiration, loyalty and support of many power brokers in the party. A Warren-Clinton race would be a heated contest that would threaten to shred all Democratic unity and could put the party in a weakened position headed into the general election. Warren has shown no signs that is what she wants. If anything, she's seemed content to focus on the issues that are important to her, like financial regulation.

Of course, 'no' right now doesn't mean 'no' forever. The current White House occupant, who promised to serve out his full term in the Senate back in 2006, is a testament to that political reality. But in the case of Warren, there's little reason to believe she will change her mind before the next presidential election.