MANILA - With a little over two weeks to go before the elections, a political analyst said Saturday that "drastic changes" can still be expected in the presidential race, as will be shown in the next voter surveys.

Speaking to radio dzMM, political science professor Edmund Tayao noted that this year's elections is unlike previous polls were likely winners emerged as early as February.

He attributed this to a higher degree of discernment on the public's part.

The latest ABS-CBN survey conducted by Pulse Asia was topped by Davao City Mayor Rodrigo Duterte who extended his solo lead from the previous survey.

But the April 5 to 10 polls, which showed Duterte as the top choice of 32% of respondents, was conducted about a week before he was heavily criticized for making light of an Australian missionary's rape and murder in his city in 1989.

During an April 13 campaign sortie in Quezon City, Duterte recalled a bloody hostage incident at a Davao prison, which killed 21 people, including Australian Jaqueline Hamill.

Duterte said he was angry that the woman, then 36, had been raped by the inmates. But he also noted that she's "so pretty he should have done it first."

WATCH: Duterte jokes about raped Australian woman

A video of his remarks has gone viral, sparking public outrage and even criticisms from the ambassadors of Australia and the United States.

READ: Duterte says he may cut US, Australia ties

In the interview, Tayao said he cannot tell yet if Duterte's popularity figures will plunge due to his controversial remarks.

But Tayao also pointed out that the presidential favorite has suffered mercurial movements in his survey ratings due to his quips.

He said that Duterte first enjoyed a rise in pre-election surveys immediately after announcinghis presidential bid.

His survey performance, however, slumped after supposedly cursing at Pope Francis last November due to the traffic jams triggered by the Catholic leader's visit in the Philippines.

Tayao said this shows the tendency of Duterte's popularity ratings to radically change at any given time.

Despite this, the University of Santo Tomas professor said that Duterte is the only candidate to recently hold the top spot in two consecutive surveys.

DUTERTE MAY WIN IF...

Tayao also said that the 71-year-old aspiring president will likely win the elections if he keeps the lead in the next two surveys.

He added that the surveys could already be conclusive of a Duterte triumph if the mayor secures a lead of at least five percentage points over his closest rival.

But Tayao also reminded the public of the limitations of surveys in terms of accuracy.

He said that the exit poll of the Social Weather Stations (SWS) in 2004 showed that former President Gloria Macapagal-Arroyo was likely to get the majority of votes in Metro Manila but election results did not validate the survey.

Surveys in the 2013 senatorial race also placed Senator Grace Poe in the eighth or ninth rank although she won the highest number of votes come Election Day.

Tayao advised voters to choose the country's next leader based on their qualifications, and not their survey performance.

"Kung magdidesisyon kayo sa iboboto niyo, wag naman iyung ibabase niyo lang kung sinong nakikita niyong frontrunner. Mamili kayo on the basis of who you actually think will satisfy your objective of changing the country," he said.

NO MAJORITY PRESIDENT

Tayao also asserted that the next Chief Executive will not be a "majority president" who wins with more than half of the votes cast.

The next president, he said, will likely only win with 600,000 votes over his or her closest rival.

"Basta mayroon kang mahigit dalawang kandidatong tumatakbong presidente, hindi ka magkakaroon ng majority presidente... Kasi nga tatlo, apat ang mga tumatakbo -- simple arithmetic iyan na sa 100%, paano ka magkakaroon ng 50% na preference," he said.

Tayao also pointed out that poll favorites President Benigno Aquino III and former president Joseph "Erap" Estrada only won by over 30% of the votes in the 2010 and 2000 elections, respectively.