Mr Chaudhary's Rashtriya Lok Dal, backed by the Congress, SP and BSP, won the Kairana Lok Sabha by-election in Uttar Pradesh this week, boosting expectations that a united opposition could damage the BJP's election-winning machine.
"If things can be managed properly in Uttar Pradesh, the 2019 poll results will be different. The fact that the three main parties -- the Congress, the Samajwadi Party and the RLD -- are being led by a new generation of leaders will be most helpful," said Mr Chaudhary, 39.
He said the new-generation leaders carry no burden of history and are comfortable with each other, and this can be translated into providing a political alternative, he added.
In Karnataka, the Congress is also the alliance partner of the regional party Janata Dal Secular, which formed the government in the southern state after sealing a last-minute deal, despite the BJP emerging as the single-largest party but short of the halfway mark.
In states where the Congress is the main party, the RLD leader suggested that the regional parties should support Rahul Gandhi's party. "While in the others, where the regional parties are in the vanguard, the Congress will have to play the supporting role."
Even in Madhya Pradesh, the Congress appears to be trying to replicate the Karnataka success by joining hands with Mayawati's Bahujan Samaj Party to face the assembly election, scheduled later this year, together.
Mr Chaudhary, son of RLD chief Ajit Singh and grandson of Jat leader Charan Singh, was a parliamentarian from Mathura.
"Coalition politics is nothing new for the country as it helps in giving representation to the diversity of the country," he said, adding even PM Modi and UP Chief Minister Adityanath are leading coalitions.
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