Barack Obama announced his candidacy for president in February 2007. But even before that, the writing was on the wall: this presidential campaign would be historic, contentious and lengthy—as NEWSWEEK's cover from Dec. 25, 2006 attested. "Obama & Hillary are already squaring off over 2008," the issue declared. Over the next 23 months, a huge field of both Democrats and Republicans would fight tooth and nail for their party's nomination, culminating in the fierce battle between Obama and John McCain. NEWSWEEK looks back at the seemingly endless campaign by presenting all of our politics covers from the last two years (there were 38 of them!), along with links to the cover stories and related video and photo galleries.