JACKSON, Mississippi (CNN) -

Lifelong Democrat Jackie Bland is doing something she never thought she'd do: Urge people to vote for a Republican.

Bland supports Thad Cochran, a six-term Mississippi senator who's trying to fend off a fierce tea party challenge to his seat from Chris McDaniel as voting got underway in Tuesday's primary runoff.

Two weeks ago, Bland helped put up 5,000 pro-Cochran posters in black communities and talk to people about his record.

"We wanted to raise the awareness to African-Americans that we do have a stake in this runoff election," she said.

She pointed to Cochran's efforts to secure federal funds for jobs, Head Start programs and health centers relied upon by African-Americans in the state.

"We don't want to move backwards," she said.

Bland's efforts reflect the high stakes locally and nationally in the Cochran-McDaniel showdown and also illustrate the unscripted political realities of particular states that play out on Election Day.

In this case, it's apparent that Cochran needs Democrats to keep his job, and some Democrats heed the fact that Democratic Senate nominee Travis Childers likely won't win in November, so they turn out for a Republican.

In Mississippi, neither candidate secured 50% of the vote in the GOP primary this month, requiring a runoff election. And both sides over the past few weeks have relentlessly pursued get-out-the-vote efforts.

Mississippi law allows anyone to vote in the runoff, meaning Democrats can go to the polls so long as they didn't vote in the Democratic primary and they don't plan to support their party candidate in the general election.

The question is whether Cochran can shore up enough support to beat back the tea party wave against him. McDaniel got about 1,400 more votes than Cochran in the primary, and national conservative groups have actively rallied around the challenger.

Cochran is pushing his message that his experience makes him more influential in Congress, and his ties on Capitol Hill will better serve Mississippi if he's reelected.

McDaniel and allies, however, say Cochran has been in office long enough, and his tenure only breathes more life to the status quo. For his part, McDaniel vows to bring change to the nation's capital and shake things up on Capitol Hill.

"The people of this country are finally waking up again and recognizing that Washington's been broken for a long time," McDaniel said Monday, referring to tea party victories in recent years. "All the sudden you see a great awakening among all the people, particularly those who are very dissatisfied with the direction our country is going."

Courting the African-American vote

Mississippi Conservatives, a super PAC founded by former Gov. Haley Barbour and his nephew, Henry, has taken the lead in courting votes from Democrats, especially in the African-American community. Cochran's allies are arguing the case that he has long been there for the voting bloc and would better represent their interests than McDaniel.

The issue is so complicated that even Bland can hardly stomach what she's doing. She attended an event Monday featuring Republican Sen. John McCain, who called on voters to keep Cochran in Washington but also spent much of his speech blasting President Barack Obama.

Bland, a supporter of the President, got up and left.

Cochran acknowledged Monday he would likely benefit if a wide range of voters turn out for the runoff.

"I've always reached out and benefited from support from the black community," he said. "My responsibility as a United States senator has been to represent the people of the state of Mississippi, not just one party or one race or a select group of friends."

But another Mississippi political veteran labeled the vote courting a risky move.

"It might get him some votes, but it might lose him some votes," said former Republican Sen. Trent Lott. The ex-Senate majority leader not only served with Cochran for many years, but the two were competitors for the leadership position in 1996.

Lott now describes Cochran as "a good friend" and said he's "very nervous" about the runoff. It will be "difficult for Thad to overcome the momentum" by McDaniel, he predicted.

Vote underway

Conservative groups are working with Christian Adams, a former Justice Department official, to train volunteers to monitor poll workers and make sure they check to see whether Democrats have already voted in their primary.