A blue oasis in the heart of the predominantly Republican Rocky Mountain West, Denver could lose its bid to lure the 2008 Democratic National Convention unless it can win the support of an important constituency — labor unions.

The city's prospects for securing the convention were boosted in Tuesday's election by Democratic victories across Colorado — including the pickup of the governor's office and a House seat. They showed the party's success in making inroads in normally GOP terrain.

Denver also boasts a renovated convention center and a flashy new hotel.

What it does not have, at least yet, is the support of union members. Without it, Denver has no chance of beating New York City in the competition for a political plum.

Denver has asked the AFL-CIO for a resolution of support. But state union officials, unhappy about what they call the city's "unfriendly" attitude in the past, are holding out for a sign of Denver's support in return.

"If they show their support for labor, labor will support the Democratic National Convention," said Steve Adams, president of the Colorado AFL-CIO.

Leslie Moody, executive director of the Denver Area Labor Federation, which represents about 80 unions, said the group wants a union contract for employees who work for the primary convention hotel, the new Hyatt Regency at Colorado Convention Center, and a contract with the Democratic National Committee that spells out a requirement for workers in the service, hotel and entertainment industries.

One obstacle to union support for the convention was resolved in October when the city agreed that workers at the Hyatt could unionize. The city had a say in the question because its bonds helped finance the hotel.

Moody said it now is up to the city to pressure hotel managers to agree to a labor contract and for the DNC to include union protections in its contract with the city.

Moody said Denver's public and private sectors have a checkered history dealing with unions. An April transit strike against the Regional Transportation District, which is largely independent of city government, left a lot of bruised feelings.

Gary Horvath, a researcher at the Leeds School of Business in Denver, said unions have struggled in the Rocky Mountain West, in part because the region lacks the types of industries where labor traditionally thrives and partly because of the leave-me-alone, independent spirit of many Westerners.

"The entrepreneurial spirit is very much alive in the West," Horvath said.

He said the convention is an opportunity for unions to show they still have clout and relevance outside their core region.

So far, 47 members of Congress in 24 states have thrown their support behind Denver's bid for the convention.

DNC Chairman Howard Dean will make the final decision by the end of the year on which city will host the convention.

Luis Miranda, spokesman for the DNC, said the party has "two great bids from two great cities."

Minneapolis-St. Paul landed the GOP's 2008 event.

Colorado's three incumbent Democratic U.S. House members — Diana DeGette, John Salazar and Mark Udall — and Democratic Congressional Campaign Committee Chairman Rahm Emanuel of Illinois wrote Dean a letter saying Democrats should "focus long-overdue attention to the West."

"Although once solidly a red portion of the country, Colorado and the Rocky Mountain West are rapidly trending blue," the letter said.

It does not hurt Denver's cause that the latest Democratic gains in Colorado build on victories two years ago, when Democrats captured a House seat and a Senate seat that had been held by the GOP, and in the same election they took control of the state House and Senate for the first time in 42 years.

Indeed, some political analysts now color Colorado purple — a blend of Democratic blue and Republican red.

DeGette said selecting Denver "will demonstrate that our party is serious about reaching out to people off the East Coast and California."

Debbie Willhite, a consultant for the host committee, said labor is crucial to Denver's bid because members of organized labor make up about 40 percent of the national convention delegates, and the national party labor support to win elections.

The last time Denver played host to a major political convention was in 1908, when Democrats nominated William Jennings Bryan of Nebraska. He was defeated by Republican William Taft.