This is a big day for the presidential campaign, with the primaries in Oregon and Kentucky practically guaranteed to clinch a majority of pledged delegates for Barack Obama.

Polls in Kentucky show Clinton on track for a two to one win in Kentucky, as she has performed best against Obama in the Appalachian region. Obama, meanwhile, is favored to win Oregon by a strong margin. Kentucky has 51 pledged delegates, and Oregon has 52 -- and with Obama only needing less than 20 delegates to clinch the pledged majority, he'll get more than he needs to reach that goal.

The question then becomes how the two camps spin the results, and whether the Obama camp plays it up as a genuine victory mark for the campaign. Obama himself has said he won't, but the Hillary camp has already been pre-rebutting that idea, calling it a "slap in the face" to the millions of people who have voted for her.

The first polls close at 6 p.m. ET in Kentucky, followed by western Kentucky at 7 p.m. ET. Oregon's mail-in voting ends at 11 p.m. ET.