Thousands of New Mexicans have already voted and Election Day is only weeks away. Which means politicians around the state are in high gear spreading their respective messages through commercials and campaign events.

But one tactic many politicians are also using to signal undecided voters is endorsements from high-profile politicians. A New Mexico political scientist said those major endorsements will impact the election but it’s not entirely clear how much it will help or hurt campaigns to get a stamp of approval from a former U.S. president, a New Mexico governor or a sitting U.S. Senator.

University of New Mexico political science professor Lonna Atkeson told NM Political Report those endorsements only go as far as the endorser’s approval rating. For example, she said, New Mexico will not likely see a visit from President Donald Trump—whose approval rating is hovering around 40 percent—in support of a local Republican candidate.

In early August, former Democratic Governor Jerry Apodaca surprised many in his party when he publicly endorsed Republican U.S. Rep. Steve Pearce for governor over the Democratic candidate, U.S. Rep. Michelle Lujan Grisham. In an opinion column published in several newspapers, Apodaca said Pearce, not Lujan Grisham, will work across political party lines.

Weeks later, just after Libertarian U.S. Senate candidate Gary Johnson announced his campaign, Republican U.S. Sen. Rand Paul from Kentucky announced his support for the former Republican two-term governor.

“Gary Johnson is a true fiscal conservative,” Rand wrote in an announcement. “As Governor, he reduced the size of government while improving services.”

Then, earlier this month former President Barack Obama offered up a second round of his political endorsements, which included Lujan Grisham, her running mate Howie Morales and four Democratic legislative candidates. Obama also previously endorsed Congressional candidate Deb Haaland and two state House candidates.

So do major endorsements like these matter?

The short answer, Atkeson said, is “absolutely,” but it’s also complicated.

For example, Atkeson said, the endorsement of an unpopular president in a midterm election may not be what campaigns want right now.

“These things definitely fluctuate with the times, so you’re not going to have the president come and endorse you and stump for you if he’s not a popular character,” Atkeson said.

A poll by Morning Consult released in March showed political endorsements by political figures are less effective than in previous years, but that endorsements can still help influence partisan voters. For example, the poll showed that Democratic voters are more likely to vote for a candidate endorsed by Obama, whereas Republicans are more likely to vote for a candidate endorsed by Trump.

But it’s still hard to judge how well these endorsements will help candidates in New Mexico. Apodaca, for example, hasn’t been in office for almost 40 years, although his son was a gubernatorial candidate in the Democratic primary this year. Paul has seen relatively high approval ratings, albeit in his home state of Kentucky. Obama’s endorsements could prove to be helpful for Democrats. But, Atkeson said, an Obama endorsement could also send a different message to Republicans.

“Obama could be mobilizing to Republicans for all we know,” she said.