India's ruling Congress party has finally shown its hand by anointing Rahul Gandhi to its second most powerful position. This appointment means that the next elections are likely to be spearheaded by Rahul against the principal opposition party's main man, Gujarat Chief Minister Narendra Modi.

The two national parties, Congress and the Hindu nationalist Bharatiya Janata Party (BJP) will be locked in a head-to-head battle in May 2014.

But neither party has chosen to officially declare their next candidate for prime minister, for different reasons.

For Congress, Rahul is the party's lone hope and it doesn't want to squander him.

As the great-grandson of India's founding prime minister Jawaharlal Nehru and the grandson of iconic female prime minister Indira Gandhi, Rahul is the scion of India's most powerful political dynasty.

But Congress fears burning off the value of his name before the polls, and frets about what might happen if he loses. Rahul is the party's ultimate weapon, and the party would not like it to misfire.

As for Modi, there are difficulties galore when it comes to declaring him candidate.

Though the BJP has at the 11th hour discarded its outgoing scandal-ridden president Nitin Gadkari in favor of Rajnath Singh, who has been BJP chief once earlier, the party is highly divisive, unlike the Congress.

This is an important advantage Rahul has over Modi. The Congress is a monolith, unlike the fractious BJP.

Congress has traditionally been led by a single leader and that leader has generally come from the Nehru-Gandhi clan. But the BJP is a multi-horse chariot.

Rajnath Singh may have emerged as the BJP's new president, but the fact remains that he is not the biggest man in the party, and it is Modi who is the party's best bet at the polls.

Yet Modi faces stiff opposition from within the party from leaders like his once-benefactor and eternally hopeful candidate for prime minister LK Advani and Advani's favorite Sushma Swaraj, and allies like Nitish Kumar, chief minister of Bihar and leader of Janata Dal (United), a party affiliated to the BJP, who maintains a cat-and-mouse relationship with Modi.

Rahul's latest formal elevation in the party implies that Congress is finally ready to play its strongest card. He is just 43 yeas old and looks much younger.

In comparison, Modi is 62. Though young by Indian political standards, Modi is no match for Rahul in terms of youth appeal. And the youth vote, which played a pivotal role in the formation of a second successive Congress government in 2009, is likely to root for Rahul, rather than Modi.

But Modi is a seasoned administrator and is serving a third consecutive term as the chief minister of Gujarat, which sends 25 MPs to the Lok Sabha, India's parliament. In comparison, Rahul is a greenhorn with zero administrative experience. This is a major negative for Rahul and an important plus for Modi.

Another important factor is the image. Modi is still being chased by the communal ghost of the 2002 pogroms in Gujarat, in which about 3,000 Muslims were killed, though a whole lot of ambassadors of foreign countries, including the envoys of the West, made a beeline to Modi to build bridges after his recent poll victory.

This brings us to the last and perhaps the most important argument in the Rahul versus Modi debate. The post poll scenario of the next general elections will come down to political arithmetic.

The BJP will have to win at least 180 seats of its own in the house of 543 to push for forming a government. It is a tall order, given the highly divisive state of affairs within the party.

Congress, on the other hand, has enough alliances that it won't find it difficult to form a government even if it falls to just 150 seats on its own, as against its present strength of 206 in the current Lok Sabha. This gives Rahul a head start over Modi.

West Bengal Chief Minister and regional satrap Mamata Bannerjee has stated that Congress will go for snap polls within this year. Even if this happens, the current political arithmetic does not give much leverage to BJP over the Congress. The strength of the scandal-ridden government led by Prime Minister Manmohan Singh comes from the weakness of the BJP, the main opposition party. This should give leverage to Rahul over Modi.

The author is a New Delhi-based journalist-author and a political commentator. bhootnath004@yahoo.com.