In the vice presidential debate sponsored by the Commission on Elections (Comelec) over the weekend, Rizalito David called on all candidates to form a broad alliance to defeat the frontrunners in the surveys.

David argued there was no way all seven vice-presidential hopefuls would defeat Sara Duterte-Carpio who is way, way ahead of the field. Senate President Vicente Sotto III has a chance to catch up with her as the campaign period enters the second half.

David also argued that none of the nine presidential candidates could overturn the wide margin former senator Ferdinand Marcos Jr had built in the remaining a month and half before balloting on May 9.

A February Pulse Asia survey showed Marcos Jr. had 60 percent support against Vice President Maria Leonor Robredo’s less than 20 percent. A separate poll by Social Weather Stations (SWS) had Marcos Jr. with 46 percent against Robredo’s less than 20 percent. It’s narrower but the only son and namesake of the late dictator still had a commanding lead.

Pollsters say it’s still possible to catch up with Marcos but it might be difficult to overtake him with less than two months before elections.

David might have been influenced by the polls to make an appeal to other candidates to unite and defeat Marcos Jr. and Duterte-Carpio. He might be watching what had happened in South Korea when all the opposition candidates banded together to defeat the ruling party’s candidates.

On a quicker look, David’s appeal might be practical and workable. It might narrow down Marcos Jr. and Duterte-Carpio’s lead in the polls. Sotto has a chance to defeat Sara and Robredo can have a fighting chance to win another come-from-behind victory, duplicating her vice-presidential win in 2016.

But this could be wishful thinking. There is no guarantee that if the other candidates will withdraw, their supporters will go to Robredo. Marcos Jr. could be strengthened if some supporters shift to him rather than Robredo.

For instance, both Marcos Jr. and Manila Mayor Francisco “Isko Moreno” Domagoso have the same support group. Some groups who supported President Rodrigo Duterte have opted to join Moreno’s campaign, like former agrarian reform secretary John Castriciones.

Moreno has been working hard to get the endorsement of the president and he has been sustaining his attacks against Marcos Jr. on the P203-billion unpaid tax of the Marcos estate.

In 1997, the Bureau of Internal Revenue assessed that the Marcos family had to pay the government P23 billion in estate taxes after the dictator died in 1989. This was based on the 60 percent estate tax on about P38 billion in assets which the government had failed to confiscate or recover.

More than P300 billion had been seized but P125 billion pesos remained under litigation. The estate tax covered properties and assets that the Presidential Commission on Good Government (PCGG) had failed to identify and recover.

At least 11 properties, which were found to be owned by the Marcoses, are attached to the estate tax case. Marcos Jr. has no more excuses but to pay the government and enjoy the wealth left behind by his father legally.

It is still uncertain if Moreno’s attacks have been affecting Marcos Jr.’s numbers unless the March survey is released by Pulse Asia and SWS. Forget the other surveys done by other pollsters.

Moreno’s attacks were designed to chip away support from Marcos Jr. and transfer to him because people who support Marcos Jr. will not likely go to Robredo. If there are any, it will be a small fraction.

Moreno was determined to take away support from Marcos Jr. which he believed was not a solid support. Some political analysts have said that support for Marcos Jr, remained soft. Only about 20 to 30 percent are diehard Marcos loyalists. The rest are swayed by his promise of “ayuda” and other propaganda. These supporters can shift support anytime.

Sen. Emmanuel “Manny” Pacquiao ranked fourth in the surveys, showing substantial support in the Visayas and Mindanao. If he does not withdraw, there is no way the Marcos Jr. and Duterte-Carpio team could sweep votes from the south.

Pacquiao has considerable support from Mindanao. It will break the monopoly of the “uniteam” of voters’ support. Robredo would probably get Pacquiao’s voters if he withdrew, but it would be minimal. It is in Robredo’s interest to keep Pacquiao in the race.

Sen. Panfilo “Ping” Lacson’s numbers are insignificant. But his supporters would likely shift support to Robredo if he withdraws. His political vehicle, Reporma Party, has abandoned him and has thrown support behind Robredo. It has considerable support in Mindanao and in the Southern Tagalog region, strengthening Robredo’s numbers in the two regions.

The battleground remains in the Lingayen to Lucena corridor, which includes Metro Manila. In the 2016 vice-presidential race, Marcos Jr. dominated this corridor, with Robredo winning pockets of victories in Tarlac and Batangas.

In the May balloting, Marcos Jr. is projected to win hands down in the three northern Luzon regions, but his margin could not be as big as winning by 80-90 percent of the votes in the 2016 vice presidential elections. Robredo has considerable support in the Cordillera and Cagayan Valley regions. If she gets 10-20 percent in these regions, it would be enough to turn the tide.

Marcos Jr. is weak in the Visayas and Mindanao and his strength was largely because of Duterte-Carpio’s support.

However, there are some recent developments that could take away votes from Marcos Jr.

There is an emerging Robredo-Sara (RoSa) campaign in the northern and western Mindanao regions led by Cagayan de Oro congressman Rufus Rodriguez and Mayor Oscar Moreno and Zamboanga City Mayor Beng Climaco.

The RoSa campaign could help Robredo win support in areas where she was weak in the 2016 vice presidential elections. There were talks the Moro Islamic Liberation Front (MILF) leadership and Basilan kingpin Mujiv Hataman would make her win in their areas.

The crowd at her campaign rallies are encouraging signs of support for her candidacy. It could prove the surveys wrong. Robredo has the momentum. If she could sustain it until May 9, there’s a chance she could score another upset victory.

There is no need for other candidates to withdraw. David has a noble purpose to defeat Marcos Jr., but Robredo will try to make it on her own to win.