In case of a hung house, the Governor has no clear rules to go by. The Constitution empowers a Governor to appoint a chief minister, but remains silent on the order or precedence in case of a fractured mandate. So it is entirely his discretion, whom he asks to form government.
"It is a matter of constitutional propriety," said constitutional expert and former Solicitor General Harish Salve. Normally the single largest party is called to form government, he said. But "If someone says he has numbers, the Governor has to look at it... Whoever is called must prove majority within a week," said the ace lawyer, who used to be one of the government's top law officers.
Two commissions that explored the Centre-state relationship advised that in case of a hung house, the single largest party that can show majority be called upon to form government. If it is unable to do so, only then a post-poll alliance which has the numbers can be given a chance, said the 1983 Sarkaria Commission and the 2007 Punchhi Commission.
Going by this convention, the BJP, as the single largest party, is better placed. But the Congress-JD(S) combine, which has the numbers - 118 in a 224-member assembly - argue that this was not the rule followed in states like Goa and Manipur. Congress leaders argue that in both states, the party was not invited to form government despite being the single largest party. The BJP formed the government after tying up with regional parties and independents.
Tweeting a screenshot of Mr Jaitley's old tweets, CPM general secretary Sitaram Yechury argued that governors appointed by the BJP "didn't invite the single largest party" in Goa, Manipur or Meghalaya. "Union ministers gave arguments supporting them. The precedent is there to follow, right?" he tweeted.
Mr Salve was of the opinion that the courts should not be called upon to sort out everything. "We have to build public faith in our institutions," he said.