The BJP would like to abide by the law in the Karnataka case because the law benefits it this time. Unlike in Goa and Manipur, where it cared two hoots for constitutional proprieties and the law, it is the Single Largest Party here.
The law is clear, however much the so-called legal minds may say to the contrary: The Governor has to call the SLP first. BJP wants that (note the tenor of Narendra Modi speech last night), so Karnataka Governor Vajubhai Vala, unlike his counterparts in the other states, will not have to go against any legal grain.
If that happens, the first hurdle for BJP CM candidate BS Yeddyurappa is election of the speaker. What if the BJP's candidate is defeated by the joint opposition candidate? What an embarrassment! The opposition will deem it that the Yeddy govt is as good as defeated on the floor of the House!
Once this is over, then it is up to Yeddy to manage to prove his majority on the floor of the House. That he can do only by "persuading" JDS or Cong MLAs to either abstain or resign. (This is where the ability of the two parties to protect their flock is tested.) Thus the strength of the House would be lowered to allow BJP to have a majority vote even with 104 MLAs.
Thereafter, there will be 15 -20 bypolls, but that is another issue.
The Cong-JDS combine would be defying logic and political maturity if they move courts to insist a post-poll alliance be given precedence over the SLP. The BJP did the same thing in 2008 when it fell short of majority; and in any case it is merely borrowing a leaf from the book of unethical politics that the Congress had authored long ago. The Congress and JD(Secular) will in the coming days cry foul, saying the BJP money-bagged their MLAs! In private, they don't really bother. It's the noise that matters. The Congress always knew it's priority was to (a) expose the BJP's desperation to come to power, (b) show the regional party bosses that it still can call political shots and (c) boost the morale of its workers after the defeat. That it has partly achieved.
Coming back, the BJP govt, which will be in a minority, will never be able to get anything passed in the House. (At least until the bypolls are held and it manages a simple majority.) Even the Finance Bill. Then what happens? It will be a useless attempt to be in govt in such a case. If the BJP wins most of the bypoll seats, that is another matter.
Then comes the issue of 2019. Being in the opposition gives the antithetical Cong and JDS enough reason to fight the polls in alliance in the state. That will harm the BJP's LS prospects without any doubt. (On the other hand, if the Cong and JDS form the government they will start fighting like cats and dogs within months, will not see eye to eye by 2019 -- which can benefit the BJP). But then, wouldn't the BJP want to wield the reins of power in the state in order to better "oversee" its electoral performance in the Lok Sabha elections? So, the ball is entirely in BJP's court. Phyrric victory by making Yeddy CM now or try to gain more LS seats in 2019?
Just another thought: What if Yeddy is the BJP's sacrifical lamb? See, the BJP leadership has not much use for him any longer. He did his maximum, and it fell short. He has the silent anger about his son not being given a ticket. He is unhappy to be bandied about by a junior like Amit Shah. He can't deliver more in 2019. He is also getting old, quite old. How to get rid of him? Best way is to make him CM if the Governor invites himj. If he goes the Vajpayee way, so be it. But what if he, the fox he is, goes the PV way!!!
There's no end to politics!!!!