CHEYENNE - Observers say Rep. Barbara Cubin's apparent decision to retire from the U.S. House of Representatives leaves next year's Republican Party primary and the following general election wide open.

While some top Republicans say state voters are likely to insist on traditional conservative values in picking her replacement, a spokesman for the state Democratic Party says people are ready for a change.

Cubin, Wyoming's sole voice in the U.S. House since 1994, has scheduled an announcement today in Casper to discuss her plans for the 2008 election. Two Republican officials said Friday that Cubin planned to announce she will not to run for re-election. They spoke on condition of anonymity because the congresswoman has yet to make her plans public.

Jim King, head of the political science department at the University of Wyoming, said the decision would create a wide-open primary for the Republican nomination next year.

"I think we saw last spring, when the Republicans were nominating candidates to succeed Sen. (Craig) Thomas, there were a lot of people interested in going to Congress," King said. "And I expect a lot of those same people would be interested in this seat, now that it's open."

More than 30 Republicans filed papers seeking to replace Thomas, R-Wyo., after his death last June. Gov. Dave Freudenthal ultimately selected state Sen. John Barrasso of Casper from among three finalists the party presented to him.

Cubin last year received 60 percent of the vote in the Republican Primary to beat Republican challenger Bill Winney of Sublette County. She scored a narrow victory over Democratic challenger Gary Trauner in the general election, 48.3 percent to 47.8 percent.

"There were a number of Republicans unhappy with Cubin, " King said, noting there was even a Republicans for Trauner group last year. "Without the negatives that she carries into the race, the Republicans have a chance to keep the Republican guard in line."

Reports filed with the Federal Election Commission last month showed Trauner had raised far more money than Cubin. The reports showed Trauner had raised more than $168,000 since the 2006 campaign, compared with Cubin's $55,000.

As voters sort out whom to send to Washington to replace Cubin, King said he expects they will insist on a certain set of values.

"There's a pretty standard model, if you will, of a successful candidate in Wyoming," King said. "And that is someone who's going to be basically conservative, and expresses willingness to take on the federal government."

Bill Luckett, spokesman for the Wyoming Democratic Party, said Democrats intend to wait until Cubin's official announcement before responding to whatever she does.

"Beyond that, the state is hungry for leadership right now, and we have a candidate with proven leadership ability who we think would do a good job with Gary Trauner," Luckett said.

Tom Sansonetti, a Cheyenne attorney and 2008 county convention coordinator for the Wyoming Republican Party, said anyone seeking to replace Cubin must consider her conservative voting record.

"Whatever legacies Barbara ends up leaving after a 14-year career in Congress and having won seven straight elections, one would have to say that her conservative voting record is one of those legacies," Sansonetti said.

He noted that Cubin has a consistently conservative record on economic matters, social issues and foreign affairs.

"That pattern is one that likely a successor ought to pay a lot of attention to, because her voting record is one that has been repeatedly affirmed by all of Wyoming's voters seven straight times," Sansonetti said.