The ruling Liberal Democratic Party on Sunday rubber-stamped an internal rule change to extend the maximum tenure of its president from the current six years to nine, paving the way for Prime Minister Shinzo Abe to run for a third term that would last through 2021.

The revision, adopted at the party’s annual convention, represented a crucial step toward the prospect of Abe becoming the nation’s longest-serving prime minister.

What was supposed to be a triumphant moment for Abe, however, was somewhat marred by an ever-spiraling scandal that has dogged him and his wife, Akie.

The couple is now grappling with mounting allegations surrounding their links to an ultranationalist kindergarten in Osaka and its operator, which is at the center of a murky land deal that a veteran LDP lawmaker may have been involved in.

Opposition parties have pounced on the scandal, which has dominated domestic headlines, in what many in their ranks see as a golden opportunity to deal a crushing blow to the near-impervious Abe administration.

Standing in front of the podium Sunday, Abe, however, appeared undeterred, trumpeting the success of Abenomics, which he claims has boosted employment, curbed child poverty and helped Japan regain gross national income worth ¥50 trillion.

“I will give you my word that I will do my best to create a Japan that can shine at the center of the global stage,” a confident Abe told fellow LDP members attending the convention in an address.

Abe also took the opportunity to emphasize his successful summit talks with new U.S. President Donald Trump last month.

“We were able to demonstrate to the world that the Japan-U.S. alliance is not in the slightest bit shaken” by a Trump presidency, Abe told the audience.

This year marks the 70th anniversary of the enactment of Japan’s pacifist Constitution, which, since it took effect in May 1947, has remained unaltered. That has irked right-wingers who regard the U.S.-drafted supreme law as a remnant of the nation’s postwar subordination to the United States.

Abe said his party will “spearhead a concrete debate” on its revision.

The prime minister, who took office in December 2012, was originally supposed to bow out in September next year, when his current second term expires. But Sunday’s move to extend the maximum tenure of the LDP presidency from six years over two terms to nine years over three terms will enable him to run for a third term in the party’s next leadership election slated for next year.

If he is re-elected, he could theoretically remain as prime minister until September 2021, allowing him to host the Tokyo Olympics in 2020. In Japan, the leader of the ruling party normally becomes prime minister.

So far, Abe, in stark contrast to what has often been called a revolving door of hapless predecessors who often lasted for only a year or so, has proved so popular that he won the previous leadership election unopposed in 2015.

According to an opinion poll jointly conducted last week by the influential Nikkei business daily and TV Tokyo, the Abe Cabinet approval rating was hovering near 60 percent.

Among the few possible contenders who could challenge Abe is Shigeru Ishiba, an LDP heavyweight who lost to him in the 2012 leadership election. Although Ishiba hasn’t said he will throw his hat in the ring the next time around, he has nonetheless hinted that he will remain a vocal critic of the Abe administration.

Letting Abe win unopposed in the next LDP presidential race, with no real deliberation over his policy, is “certainly not a good thing for the LDP,” Ishiba told reporters after the convention wrapped up.

“If you have a difference in opinion than your party, you need to speak out and seek judgment from your fellow party members. That’s the way you should behave as an LDP lawmaker,” Ishiba said.

Another possible challenger, Foreign Minister Fumio Kishida, took a more reserved stance.

“The extension of the presidency is something we debated thoroughly and approved unanimously. … All I will do at the moment is dedicate myself to the role as a member of the Abe Cabinet,” Kishida said.

Neither of the “post-Abe” candidates, however, appear able to deal a heavier blow to the Abe administration than the ongoing scandal regarding Moritomo Gakuen, which operates the ultranationalist Tsukamoto Kindergarten in the city of Osaka. It is also slated to open the Mizuho no Kuni elementary school, in Toyonaka, Osaka Prefecture, in April.

First lady Akie Abe had been the honorary principal of the new elementary school until Feb. 23. However, she quit after allegations surfaced over the operator’s discounted land deal that some say may have been manipulated by politicians with cozy ties to Moritomo Gakuen President Yasunori Kagoike.

Abe said he would resign if either he or his wife were ever found to have had anything to do with the shady deal.

The kindergarten run by Kagoike has instructed children that attend it to worship Abe as a hero who protects Japan from regional rivals such as China and South Korea, urging them to recite a 19th-century imperial decree on education. The first lady, in September 2015, also gave a lecture at the preschool, according to a posting to her personal Facebook page.

On Friday night, a crowd of protesters gathered in front of the Diet building calling for the “resignation” of Abe and chanting, among other things: “Don’t destroy our children!” Organizers estimated the turnout at 1,200.

“A month ago, few even knew what Moritomo Gakuen was, but now it’s all over the news. What was unthinkable a month ago is now hitting the Abe government hard,” Yoshifu Arita, a lawmaker from the main opposition Democratic Party, told the crowd.

“I’d say it’s possible that we’re about to see the demise of Abe-led politics,” he added.