Sen. Kennedy has malignant brain tumor  —  BOSTON - Sen. Edward M. Kennedy has a malignant brain tumor.  —  Doctors for the Massachusetts Democrat say tests conducted after Kennedy suffered a seizure this weekend show a tumor in his left parietal lobe.  Preliminary results from a biopsy …

McCain Confronted With New Iran Gaffe, Gets Facts Wrong Again (VIDEO)  —  Yesterday, Time's Joe Klein noted that he could find no evidence that Sen. Barack Obama had ever specifically said he would negotiate with Mahmoud Ahmadinejad: … Later in the day, Klein confronted McCain with this question at a press conference.

‘Bush intends to attack Iran before the end of his term’  —  US President George W. Bush intends to attack Iran in the upcoming months, before the end of his term, Army Radio quoted a senior official in Jerusalem as saying Tuesday.  —  The official claimed that a senior member of the president's entourage …

McKinnon To Step Aside From McCain Effort  —  Mark McKinnon, the lead media consultant for Sen. John McCain's (Ariz.) presidential bid, is stepping down from that role — making good on a pledge he made last year not to work against Sen. Barack Obama (Ill.) in the fall campaign.

Talking Versus Doing  —  In 1965, Mancur Olson wrote a classic book called “The Logic of Collective Action,” which pointed out that large, amorphous groups are often less powerful politically than small, organized ones.  He followed it up with “The Rise and Decline of Nations.”

Clinton Puts Up A New Fight  —  The Candidate Confronts Sexism On the Trail and Vows to Battle On  —  Women of all ages and nationalities push against the rope line carrying books and T-shirts, posters and stuffed animals — anything for her to autograph.  They tote huge signs that shout …

Key Clinton Constituencies Moving Toward Obama  —  Obama now competitive among women, whites, and the less educated  —  PRINCETON, NJ — Gallup Poll Daily tracking has documented a surge in Democratic voters' support for Barack Obama over Hillary Clinton in recent days …

5 Questions About the Kentucky and Oregon Primaries  —  1. How many delegates are at stake?  —  Barack Obama and Hillary Rodham Clinton will split 103 delegates on Tuesday that are “pledged” to support either candidate — the delegates are almost evenly split between Kentucky (51) and Oregon (52).

Clinton Keeps Up Fight As Staff Tensions Rise  —  By MONICA LANGLEY in Bowling Green, Ky., and AMY CHOZICK in Crow Agency, Mont.  —  Heading into twin Democratic primaries Tuesday in Kentucky and Oregon — which the two candidates are expected to split — Sen. Hillary Clinton is vowing …

YouTube refuses Lieberman request  —  The chairman of the Senate Homeland Security and Governmental Affairs Committee today asked Google, the parent company of the popular online video-sharing site, YouTube, to “immediately remove content produced by Islamist terrorist organizations” …

Report Details Complaints Over Interrogations  —  WASHINGTON — F.B.I. agents complained repeatedly, beginning in 2002, about the harsh interrogation tactics that military and C.I.A. interrogators were using in questioning terrorism suspects, like making them do dog tricks and parade in the nude …