Democratic activist Barbara Eagleton – or rather, her endorsement – has become part of what is arguably the hottest issue in the 87^th District state representative contest between Stacey Newman and Susan Carlson.

The two candidates are incumbent, like-minded Democratic lawmakers tossed into the same district by virtue of the new boundaries drawn to reflect population changes in the once-a-decade census.

At issue is Newman’s list of supporters, which initially included such major Democratic names as Eagleton and Joe Edwards, founder of Blueberry Hill, a restaurant and music club in University City.

“I don’t remember endorsing anyone,’’ Edwards said. But he added that there could have been some miscommunication since he donated to both candidates. “I have called both of them and asked if I could step back," he said, and remain neutral.

Eagleton, the widow of the late Sen. Thomas F. Eagleton, says she also is a fan of both women, but that she’s told Newman that she’ll be endorsing Carlson because they’re personal friends.

Carlson campaign manager Judi Roman says several names on Newman’s endorsement list don’t belong there, and she’s raising questions about why Newman listed them. Newman ascribes any errors to “honest confusion” on the part of some supporters who initially agreed to endorse her but didn’t realize she was competing against Carlson.  Now, some – like Edwards and Eagleton – want to remain neutral or are switching sides.

The dispute prompts a broader question: Why does it matter?

“In this primary, it’s important because both of these candidates are well-known, attractive progressive candidates,’’ said Roman. Undecided Democratic voters seeing major names on one candidate’s endorsement list may think “ ‘maybe they know something I don’t, and so I’ll support her,’ ” she said.

Newman says endorsements signal “broad community support,’’ but she believes their power may be overblown, when it comes to established candidates like her and Carlson.

“It’s part of the game,’’ Newman said with a sigh. “It’s like yard signs.”

And in Missouri primary contests from the state Senate to the U.S. Senate, endorsements -- like yard signs -- are attracting lots of attention.

In the Republican contest for the U.S. Senate, for example, party activists were abuzz earlier this week when former Alaska Gov. Sarah Palin announced she was endorsing former Missouri Treasurer Sarah Steelman in the spirited three-way GOP primary.

Within an hour, one of Steelman’s rivals – St. Louis businessman John Brunner – issued a statement in which he asserted that Palin didn’t know enough about Steelman and needed to reconsider.

Why primary endorsements matter

Brunner’s reaction highlights the power that political endorsements are believed to wield – especially in primary elections.

Dave Robertson, a political science professor at the University of Missouri-St. Louis, says there areobvious reasons endorsements often are more sought after in internal party battles.

“An endorsement in a primary provides a signal … of the legitimacy of a candidate,’’ Robertson said. Voters unfamiliar with a candidate may be more likely to support them, he said, if they hear that respected figures in their party have endorsed the candidate in question.

Such endorsements, Robertson acknowledged, may only sway a small percentage of voters. But in a primary, a few voters can make big difference.

“Primaries are low turnout elections,’’ he said. “Influencing a few people can matter a lot.”

For example: In the Senate race, the potential power of former Arkansas Gov. Mike Huckabee's endorsement is seen as the chief reason the Republican candidate he supports -- U.S. Rep. Todd Akin -- has featured Huckabee in two back-to-back TV ads that Akin is running heavily in certain GOP-heavy areas of the state.

(Start of update) On Thursday, Akin announced that he had been endorsed by more than 100 pastors -- a move aimed at highlighting his standing as a staunch religiousconservative. (End of update)

On Wednesday, two area senators close to the tea party movement – Republicans Jim Lembke of Lemay and Brian Nieves of Washington, Mo. – announced they were endorsing fellow state Sen. Brad Lager, R-Savannah, in his bid for lieutenant governor.

The action by Lembke and Nieves could be seen as an attempt to swing tea party sentiment away from Lt. Gov. Peter Kinder, who has been popular with the movement because of his lawsuit against the federal Affordable Care Act. Lager is challenging Kinder on Aug. 7.

Bill Hennessy, founder of the St. Louis Tea Party, circulated Lembke's and Nieves' endorsements, lauding them as "fiscal hawks" in his daily email blast to tea party sympathizers.

On the Democratic side, the two incumbent members of Congress running in the newly drawn 1^st District – William Lacy Clay Jr. and Russ Carnahan – have been sparring over endorsements for the past couple weeks.

Each has accused the other of misleading progressive voters by failing, for example, to acknowledge that some groups  have endorsed both of them – such as Planned Parenthood of the St. Louis Region’s political arm and the Missouri chapter of the National Education Association.

Meanwhile, Republican ranks are in turmoil over the Missouri Right to Life’s endorsements issued a few days ago.

The state’s largest anti-abortion group has endorsed all three major Republicans running for the U.S. Senate and for governor – prompting sighs of relief among a number of GOP campaigns and their allies.

But Missouri Right to Life endorsed only one of three major Republicans – state Sen. Scott Rupp of Wentzville – running for Missouri secretary of state. And the group didn’t endorse either Lager or Kinder in the lieutenant governor’s contest. The only lieutenant governor candidate of any party endorsed by Right to Life was Constitution Party candidate Cynthia Davis, a former Republican.

Right to Life said in a statement that it did not endorse any candidate who had supported the 2011 passage of the Missouri Science Innovation & Reinvestment Act (MOSIRA), an incentive program sought by research facilities and universities around the state. An exception was made for candidates who backed restrictive language that was sought by Right to Life but not passed by the General Assembly.

As a result, Right to Life has not endorsed a number of prominent area Republican legislators on this year’s ballot – including the expected next speaker of the House, state Rep. Tim Jones, R-Eureka, an outspoken social conservative who said the new restrictive language wasn’t needed because of existing protections in Missouri law.

The potential power of Right to Life's snub won’t be tested on Aug. 7, since Jones doesn’t have a primary challenger. He doesn’t have a general election opponent either.