It's the New York Times, so that's not a bad assumption in general. But in this case, there's a specific reason to wonder about the partisan motivation behind the hit piece. Specifically, Marilyn Thompson -- co-author of the hit piece in the Times today -- previously accepted money from a group out to get Kentucky Senator Mitch McConnell, to research an attack piece against McConnell in the Lexington Herald-Leader. She was the editor of the Herald-Leader at the time:
In 2006, as editor of the Lexington Herald-Leader in Kentucky, Marilyn W. Thompson wanted her paper to undertake a major project examining Republican Sen. Mitch McConnell's political fundraising practices and suggestions of influence peddling. When she realized her lean newsroom budget alone wouldn't cover it, Thompson got her Knight Ridder bosses' enthusiastic approval to seek a grant from the nonprofit Center for Investigative Reporting. The California-based center provided $37,500 to underwrite the salary of reporter John Cheves, who took an unpaid six-month leave of absence to do the project, as well as to cover expenses.
Cheves was a staffer for Democratic Senator Ron Wyden at the time. At least this time Thompson's doing her own dirty work.