You must be a liberal newspaper because only a liberal newspaper would soul search, critique itself and entertain doubt about whether it had a bias.
Political Bias at the Times? Two Counter-Arguments
Do you see Fox or the New York Post or the Washington Times worrying about having a conservative bias? No, they put out a banner claiming to be fair and balanced, and go on pursuing their chosen political agenda.
It's not enough to be objective or strive for balance in the current climate. Conservative critics would be happy to claim that water had a liberal bias, if it meant that would move things in their direction. A man is considered as black if he has one drop of African blood- but in order to be considered white, he has to be lily white. Remember that old saw, 'politically correct'. The right aren't looking for fairness or balance, or the 'truth'- if it doesn't suit their agenda.
They will push the whole paradigm until 'liberal' is a synonym for 'radical', instead of a description of the outlook of fifty or more per cent of the American public.
Americans, I think, are naive, and way too trusting, when it comes to what's happening to the media.
On August 23, 1971, the U.S. Chamber of Commerce distributed the Powell Memorandum to its national membership of leading executives, businesses, and trade associations.
The Powell Memorandum was the first drumbeat signaling what the right calls the 'culture wars'. In the 70's, when liberal critics were denouncing the growing power of big business, big business struck back. Amongst other recommendations, The Powell Memorandum advised conservatives to buy up media outlets, and start up think tanks to fund journalists and writers that were amenable to their views.

"For two decades, since the installation of Ronald Reagan in 1980, the radical right has run a tightly coordinated campaign to seal its hold on the organs of power, ranging from the highest law courts to the largest corporations, from the White House to Capitol Hill, from television tubes to editorial pages, and across college campuses.
They have constructed a well-paid activist apparatus of idea merchants and marketeers -- scholars, writers, journalists, publishers, and critics. They have intimidated the mainstream media, and filled the vacuum with editors, columnists, talk-show hosts, and pundits who have turned conservatism into a career tool. They have waged a culture war to reduce the rich social heritage of liberalism to a pejorative."

The Powell Manifesto: How a Prominent Lawyers Attack Memo Changed America.
How many major media companies are owned by ultra-conservatives and how does that affect their reporting? What does it mean for freedom of the press? Should someone like the Sinclair Broadcasting Group be allowed to broadcast a faux "documentary" on the eve of the elections, and evade federal requirements of equal time by calling it news? What does it mean for the concept of an independent press when a media company, like Sinclair, looking for favorable decisions by government officials, gives overwhelming financial support to one candidate, then chooses to broadcast a program damaging to his opponent? What happens to democracy if the "information" that the public gets is cherry-picked by the media's owners, as seen in the news room memos that were collected by the producers of the documentary "OutFoxed"?
Those are the questions we ought to be investigating.
If the Times is, indeed, liberal in it's outlook, it may end up as one of the few beacons of light in a sea of media that have no loyalty to the ethics of journalism, or the concepts of objectivity, or the need for balance.