Former Alaska governor Sarah Palin addresses the Conservative Political Action Conference at National Harbor, Md., in March 2013. (Jonathan Ernst/Reuters)

Sarah Palin holds no public office. She isn't a candidate for one. Long gone are the days when she was a Republican vice presidential contender or a potential presidential hopeful. Her star has faded.

And yet Palin is in high demand this week. She is hitting the campaign trail in at least two of the states holding the most crucial races in the battle for the Senate majority: Kansas and Louisiana.

The stops encapsulate Palin's enduring relevance in a party in which she is no longer a leading figure: She can help Republicans who badly need to burnish their conservative credentials and those who urgently need to become more relevant.

Palin campaigned for Sen. Pat Roberts (R-Kan.) Thursday morning, pitching him as a staunch conservative who contrasts sharply with his main opponent, independent Greg Orman. The intent of bringing in Palin was to shore up support for Roberts on the right, where lingering frustration among some tea party voters has complicated the senator's chances. Palin still has a loyal following among tea party activists.

“I’m tea party and I’m endorsing him. I don’t know a tea partyer who isn’t endorsing him," she said, brushing aside a question about why the tea party challenger who lost to Roberts has not backed him in the general-election contest.

Roberts has recruited an army of nationally known Republican figures to come to Kansas to help bolster his appeal in all corners of the party. The diverse array of surrogates includes Sens. John McCain (Ariz.) and Rand Paul (Ky.), two lawmakers who often have clashed intensely.

For Palin, the hope is to encourage conservative voters who soured on Roberts after the primary to vote for him in the fall. Polls show a close race between Roberts and Orman. Roberts simply can't afford to lose tea party voters to apathy in November.

The former Alaska governor's role in Louisiana is a bit different. She will campaign for retired Air Force Col. Rob Maness, a underdog candidate who has claimed the tea party mantle in an all-party primary, on Saturday.

Most Republicans have coalesced around Rep. Bill Cassidy (R), the establishment favorite and the candidate who appears most capable of unseating Sen. Mary Landrieu (D).

Maness doesn't need tea party credibility like Roberts does. What he needs is more money and more name recognition. Bringing in Palin could help on both fronts.

She's such a well-known figure that she is sure to draw headlines in local news media, showering attention on Maness that he would not otherwise receive. She also can help on the money front simply by putting her name on fundraising e-mails.

As The Fix's Philip Bump noted, Palin's win-loss record has not been very good in this year's campaigns. There are questions about a lack of consistency in her endorsements. Roberts and Maness, for example, are two very different types of Republicans. Democrats have sought to use her as a campaign bogeyman.

Despite all that, and despite the fact that she isn't as big a draw as she was in 2010 or 2012, Republican campaigns continue to seek her presence in important contests. Both Kansas and Louisiana could factor heavily in which party controls the Senate next year.

As long as Republicans are looking to shore up their right flanks and tea party contenders are struggling to generate buzz, you can count on seeing Palin out there.