Tuesday's primary contests in South Dakota and Montana won't decide the Democratic presidential nomination -- but the finish line is in sight.
The closing of the polls could open the floodgates to dozens of superdelegates who haven't stated their preferences yet.
Barack Obama tells The Associated Press there are many superdelegates who have been private supporters of his but want to respect the process by not endorsing until after the final primaries.
Polls suggest Obama will win both of today's contests.
Neither he nor Hillary Clinton plans to be in either primary state tonight.
Obama has a wrap-up rally in St. Paul, Minnesota -- in the same arena where Republicans hold their party convention in September.
Clinton will have an evening rally in New York. She's giving no outward hints that she's leaving the race. But some staffers in key battleground states are shopping around resumes and contacting former employers.