While the top tier of 2008 presidential hopefuls is already crowded with headline hogs like Sens. John McCain, Barack Obama and Hillary Clinton, long shot candidates haven't given up hope of snagging at least some of the spotlight.

While their chances of winning party nominations are slim, Republicans like Sen. Sam Brownback and Rep. Duncan Hunter, and Democratic Rep. Dennis Kucinich, among other ideologically driven candidates, are in a good position to influence the national discussion ahead of the 2008 election. In the process, they will force their top-tier counterparts to talk about uncomfortable issues, help craft the party platform and even inspire future candidates or movements.

They can be, as Tennessee political science professor Sean Evans calls it, "influential losers."

"The main reason people run for higher office is either to win, or they want to promote a certain agenda or certain message with the hopes it will be adopted by the winning candidate or the party itself," said Evans, who teaches at Union University.

A Different Perspective and Voice

Byron Williams, California pastor and political columnist, said American history is filled with candidates who lost elections by big margins but played a significant role in shifting attitudes or elevating a popular cause.

"They will play a role" in this election, said Williams. "The fact is, they bring a perspective and a voice that would not otherwise be heard."

Many examples are available from past elections to demonstrate the influence of longshots. Gary Bauer, for instance, knew he had little to no chance of winning the Republican nomination in 2000, but he offered himself as the religious conservative candidate in a broad field of Republicans.

While then-Texas Gov. George W. Bush eventually got the party nod, Bauer said he felt like his candidacy meant something.

"I had asked George Bush whether he would appoint pro-life justices to the Supreme Court," he said, recounting how he was given several fortuitous opportunities to ask the future president direct questions during the debates. Each time, he pressed Bush about judges.

What eventually emerged, he said, was a pretty strong indication that Bush would not let abortion opponents down on the issue. In his second term in office, Bush got two conservative justices on the Supreme Court.

"I felt great about it," Bauer said about the experience, noting that he was able to say what was on his mind during the debates while the top tier GOP candidates, who at the time also included McCain, glistened on stage from the perspiration caused by being "so full of pollster and consultants' advice."

A dozen years before, evangelical Republican Pat Robertson mobilized the religious right during his unsuccessful primary run in 1988. On the left, civil rights giant Rev. Jesse Jackson ran for president twice and surprised pundits by winning five primary contests — all in the South — in 1984 and 11 in 1988. The victories secured liberal wings of delegates at the Democratic conventions.

In 1992, long shot conservative Pat Buchanan's fiery speech on the American culture wars underscored the divisions in the party and stole much of the show at the Republican National Convention. President George H.W. Bush won the nomination for re-election, but Buchanan's speech sparked an era of new Christian conservative influence in Washington, analysts say.

Separately, it was the other long shot of 1992 — independent Ross Perot — who had the biggest impact. He forced both Bush and then-Arkansas Gov. Bill Clinton to talk about deficits and fiscal responsibility. He grabbed 19 percent of the popular vote — much of that assumed to be disaffected conservatives — sending Clinton to the White House.

Someone For Every Issue

Today's long shots have a variety of causes on which to focus their laser-like attention.

Hunter, the former chairman of the House Armed Services Committee, opposes abortion and free trade policies that he says are promoting massive trade deficits and lopsided global relationships. He also has strong opinions on creating tough immigration reforms to tighten up illegal border crossings.

The representative from San Diego County told FOXNews.com that he is being embraced by conservatives who aren't thrilled with the prospects of McCain or former New York City Mayor Rudy Giuliani as their nominee.

"I think my message uniquely resonates with the American people at this point in history," said Hunter, 59, who is in his 14th term representing California's 52nd District. "We'll see if I can attract a crowd."

Whereas Hunter fills the need for tough immigration law candidate, Brownback, 50, says he is the religious right's best bet, the guy to dust off this voting bloc's once legendary influence and bring it back into prominence among Washington's power brokers.

Brownback, first elected in 1994 and now serving his third term in the Senate, timed the announcement of his candidacy to coincide with the March for Life on Jan. 22.

A staunch anti-abortion legislator whose causes in the past have included a government-imposed "family hour" for television programming, he frequently peppers his remarks with talk of God and religion and how to keep both in Americans' cultural and civic lives.

"I've voted on these issues of life and marriage — many of the other social issues. I've been a leader on those issues," Brownback told "FOX News Sunday." "I've been a tried and true leader on these core issues to the base of the Republican Party and also core to America."

In Far Left Field

Kucinich, who this month began his 6th term representing Ohio's 10th District, which includes the city of Cleveland where he used to be mayor, made an unsuccessful run for the 2004 Democratic nomination. In his Dec. 12 announcement that he would run again, he repeated his staunch opposition to the war in Iraq. He also put his own party on notice: they cannot squander the 2006 mandate from voters with unfulfilled promises.

"Somebody didn’t get the message," he said of Democratic leaders, who so far have not demanded a withdrawal of U.S troops from Iraq. "What kind of credibility will our party have if we say we are opposed to the war, but continue to fund it?"

Depending on which way the already unpopular war goes, Kucinich, who embodies the Democratic caucus' progressive wing, could force the hand of top-tier Democrats like Clinton or potentially Obama to pay more attention to the anti-war voices in the party.

"Dennis Kucinich is going to force that conversation," said Williams.

Tougher These Days for Longshots

While other candidates are also considered longshots — among them, Rep. Ron Paul of Texas, former Virginia Gov. Jim Gilmore and former Alaska Sen. Mike Gravel — everyone running actually does want to win the election for the White House.

Their odds are further limited by the money races, said John Gizzi, political editor of the conservative magazine Human Events. Gizzi said it has been harder for longshots and dark horses to emerge because today's campaign system rewards well-financed insiders early on in the process.

"For the most part, conventions have been coronations," not contests, as nominees are all but chosen during the state primaries and little is left to do but speechify, said Gizzi, adding that minor candidates, particularly those who offer little celebrity, are often shut out of that, too.

"How can Duncan Hunter — a very able man and good person — affect the platform, when he may not even get a speaking part because the podium is saved for candidate X?" he asked.

Analysts say it will be difficult for Hunter and others to persevere, particularly when estimates are already floating that candidates will need to earn $100 million this year to be competitive in next year's election.

"The price of admission has gone up," said Williams.

Hunter is tapping into the conservative base for funds, but says he doesn't have to worry so much about expensive consultants and political strategists to shape his image. He's counting on his conservative credentials to get him noticed where it counts.

"Typically, the field of contenders have to create a conservative image for the primary voter," he said. "I'm going to be able to save a lot of money because I am conservative."

Conventional wisdom might dictate that a candidate closer to the political middle has a better shot at winning the presidency, but candidates who capture the energy of the party base left or right of that center win primaries, say analysts.

Hunter may appear too far right for a general election, but he can mobilize the party faithful, particularly after sponsoring and passing legislation in 2006 to build a security fence on the U.S-Mexico border.

"The conservatives have not found someone to rally behind," Evans said. Hunter can fill that void enough to set the debate to the right.