By Dave Graham

MEXICO CITY Mexican President Andres Manuel Lopez Obrador's verbal attacks on a charismatic opposition rival have raised her profile and fed concern among some supporters that far from derailing her campaign for the presidency, he is undermining his own party.

Since Senator Xochitl Galvez announced on June 27 that she was running for the top job, the leftist Lopez Obrador has mentioned her by name more than 50 times during his daily press conferences - and public support for her is growing.

A computer engineer of Indigenous background with a playful sense of humor and shrewd political instincts, Galvez has lifted a flagging opposition into believing it can compete with the popular leftist Lopez Obrador as his party seeks a successor.

The president has depicted Galvez as the candidate of a corrupt elite, and last week stepped up his political broadsides by publicizing her purported business dealings, prompting her to accuse him of abuse of power.

"With everything he's doing, what it tells you is that he's afraid," said Alfa Gonzalez, a former Lopez Obrador supporter who is now an opposition mayor for the center-left Party of the Democratic Revolution (PRD), the president's old party.

Neither the president's office nor Galvez, who represents the center-right National Action Party (PAN), replied to requests for comment.

The pugnacious Lopez Obrador is the National Regeneration Movement's (MORENA) core electoral asset, and his enduring appeal is central to the ruling party's hopes of securing a second consecutive term in next year's presidential election.

By law, Mexican presidents can only serve a single six-year term. MORENA is heavily favored to win, polls show.

Since June 30, Lopez Obrador's approval rating has fallen nearly 3.5 percentage points to 58.4%, according to a daily tracking poll by polling firm Consulta Mitofsky.

Galvez, who has described growing up in poverty and selling jelly on the street, says she is of humbler origins than MORENA's main presidential contenders, former Mexico City mayor Claudia Sheinbaum and ex-foreign minister Marcelo Ebrard.

Lopez Obrador has sought to break this narrative by branding Galvez a millionaire, said Roy Campos, Mitofsky's director.

Not everyone appreciates it.

"The president should be looking out for the public, not who he can mess with," said Gabriel Islas, 48, a Mexico City resident who urged Lopez Obrador to stop picking on Galvez.

But some arguments are sticking.

"(Galvez) is a friend of the PRIAN," said 61-year-old school teacher Beatriz Vazquez, using a slight favored by Lopez Obrador to conflate the PAN and rival-turned-ally the Institutional Revolutionary Party (PRI) as defenders of monied elites.

TURNING TABLES

Galvez has hit back at the president, and this month filed a complaint with the electoral authority saying he was breaching impartiality rules.

"What the president wants is for me to quit," she said after he released her finances. "But he won't succeed."

The authority this week ordered Lopez Obrador to remain neutral and abstain from election comments. He said he would "pause" such remarks, but he and aides continue making allusions to her.

Some Lopez Obrador loyalists see in his treatment of Galvez echoes of how he suffered as mayor of the capital at the hands of his adversary, then-president Vicente Fox of the PAN, in a case known in Spanish as the "desafuero."

Under Fox's government, Congress in 2005 stripped Lopez Obrador of immunity from prosecution over a minor land dispute. The case was later dropped but sparked major protests and bolstered Lopez Obrador's popularity ahead of the 2006 presidential election.

He narrowly lost and was defeated again in 2012 before finally winning in 2018 by a landslide.

"The mistake Fox made with Andres Manuel, the president is now making with Xochitl," said a senior Mexican official who declined to be named, noting that Galvez's rise could boost the opposition's presence in Congress in 2024.

It also risked making Galvez better known than Sheinbaum, who is many analysts' leading contender, the official added.

Lopez Obrador has acknowledged some allies want him to keep quiet rather than "build up" Galvez. But, he said, the public must know she had "gone from selling jelly to being a millionaire."

Lorena Villavicencio, a MORENA politician backing Sheinbaum, said Galvez's financial affairs should have remained private and subject to the proper authorities. She urged her party to avoid resorting to tactics used against Lopez Obrador in the past.

"Negative campaigning is counterproductive," she said. "And tends to put whoever's on the receiving end in the spotlight."

(Reporting by Dave Graham; editing by Susan Heavey)