Barack Obama is doing well with his usual supporters in Montana and South Dakota, according to exit polls taken on Tuesday's primary day, but Hillary Clinton is still keeping a tight grip on her core groups in South Dakota.

In Montana, Obama is winning all of his usual voting blocs, and some of Clinton's. He is winning with women, lower income voters, gun owners and rural voters.

Clinton is winning several groups in the Mt. Rushmore State: 65 percent of seniors, 57 percent of women, 61 percent of those making less than $50,000 a year and 56 percent of rural voters.

In both states voters were asked if they would want to see Clinton as Obama's vice presidential running mate. Fewer than half of Montana Democrats said they want Obama to pick Clinton as his vice president. Barely half answered the same way in South Dakota.

Obama supporters, in particular, were cool on Clinton as running mate -- 36 percent of his backers in Montana want Clinton; in South Dakota, it's 40 percent.  A good 70 percent of Clinton supporters in both states said they want her on the ballot.

Clinton supporters in both states were asked how they feel about the prospect of Obama being the nominee. In Montana, 59 percent of Clinton voters said they'd vote for Obama in November. That number was 61 percent in South Dakota. That total went up to 75 percent when all Democrats were asked the same question.

But voters also said they think Obama has a better chance to beat presumptive Republican nominee John McCain. In Montana, 58 percent said Obama has a better chance to beat McCain, just 34 percent said the same of Clinton.

In South Dakota, 48 percent said Obama is more electable, but almost as many -- 47 percent -- said Clinton.

Asked about the protracted nomination process, 55 percent of South Dakota Democrats said they are fired up about the election while 39 percent said they feel that it has divided the party. In Montana, 46 percent say they're energized while almost the same amount said the party is at odds over the long fight.