South Dakota Sen. Tim Johnson reaffirmed Tuesday that he will switch his earlier pledge to vote for Barack Obama at the National Democratic Convention to Hillary Rodham Clinton if Clinton wins the South Dakota primary today.

Rep. Stephanie Herseth Sandlin, however, said she will stick with her pledged vote for Obama, regardless of how the primary vote turns out.

Johnson and Herseth Sandlin are two of South Dakota's seven so-called superdelegates to the national convention. Their individual votes count in addition to the 15 Democratic delegates to be awarded proportionally in today's primary between Obama and Clinton.

Unlike the election delegates, the superdelegates can vote for the candidate of their choice, regardless of who wins the primary.

Johnson has criticized the superdelegate process because he fears they could overturn the popular vote in party primaries. And many superdelegates have been steadily courted by Obama and Clinton in their long, close campaign.

Johnson cast his primary vote for Obama by absentee ballot but said he would give his superdelegate vote to the candidate who won the state. Herseth Sandlin confirmed through Deputy Chief of Staff Russ Levsen Tuesday afternoon an earlier decision that she would not switch her Obama pledge, even if Clinton won the state.

"Rep. Herseth Sandlin believes Sen. Obama will be the best president for South Dakota and for rural America," Levsen said by e-mail. "She looks forward to working with him on South Dakota's priorities after the election in November."

An independent poll taken last weekend indicated that the New York senator had a substantial lead going into Tuesday's election. But even with a Clinton win in South Dakota, Obama was likely to the reach the needed number of delegates to win the nomination this week.

If Obama is the nominee, Clinton could release her pledged superdelegates from that commitment. They could then support Obama at the Democratic National Convention. If that happens, Johnson could maintain his earlier pledged vote for Obama at the national convention in August, although he would not be required to.

Both Johnson and Herseth Sandlin are running for reelection this year. Three Republican candidates were on the primary ballot Tuesday for the right to challenge Johnson in the general election. Rapid City businessman Chris Lien was the lone Republican candidate for the U.S. House, and is preparing his challenge against Herseth Sandlin.

Asked Tuesday evening about Herseth Sandlin's decision to vote for Obama regardless of the primary, Lien said: "Ultimately, I believe it will be up to those in South Dakota to decide whether they think they are being best represented by this decision."

Johnson campaign manager Steve Jarding said by e-mail Tuesday evening that the senator's commitment to vote in accordance with the primary outcome is more than a symbolic gesture, even if Obama is ultimately the nominee.

"Tim's pledge is designed to say that if this does go to the convention and is still contested, he will cast his vote for Hillary," Jarding said. "Of course, if she concedes and releases delegates, he then can do what he wants to do - stay with her of go with the then-acknowledged nominee."

Jarding said the "end product is not always a unanimous call" at the national convention.

Other South Dakota superdelegates are former Sen. Tom Daschle, state party Chairman Jack Billion of Sioux Falls, party Vice-Chairwoman Cheryl Chapman of Rapid City, National Committeeman Nick Nemec of Holabird and National Committeewoman Sharon Stroschein of Aberdeen.

Daschle, a national campaign co-chairman for Obama, also has already pledged to the Illinois senator. So have Billion, Nemec and Stroschein. Chapman has not publicly pledged her support.

Contact Kevin Woster at 394-8413 or kevin.woster@rapidcityjournal.com