Priyanka Vadra caught the BJP flat-footed earlier this week, when she publicly championed her controversial businessman husband, Robert Vadra. The signature Priyanka move — unpredictable, subtle and impactful — rattled the ruling party.

The BJP's complacency vis-a-vis Priyanka is based on the assumption that Vadra, under investigation by the Enforcement Directorate for suspected money laundering, is her Achilles' Heel. By tackling the contentious issue head-on, she spiked the BJP's guns and ensured that the Congress, despite being vaguely embarrassed by his shenanigans in the past, now stands firmly behind him.

Priyanka's unpredictability makes it impossible for the BJP to anticipate her moves, but it is the least of her many political strengths. She comes across as a natural-born leader; charismatic, combative, forthright and never at a loss for words, in sharp contrast to her bland and occasionally jejune sibling, Congress president Rahul Gandhi.

Accustomed to dealing with Rahul's forced pugnacity, the BJP will have a hard time countering her innate combative vigour in Purvanchal. The party rank-and-file have responded to her advent with an enthusiasm Rahul has never been able to inspire. Middle-rung Congressmen declare with absolute confidence that with her at the helm, it is only a matter of time before the Congress re-takes UP.

Priyanka's air of command is inborn; she channels her grandmother, Indira Gandhi, with a touch of Princess Di. The resulting combination of strength and compassion is an advantage she shares with Prime Minister Narendra Modi and one that always plays well with the electorate.

Her bouquet of virtues includes sharp political instincts and the common touch, both of which her brother lacks. She effortlessly recalls the names of key party workers and handles them in a firm-yet-friendly fashion, often inspiring slavish adoration. On the campaign trail, her connect with the voters is palpable. Like the late Atal Behari Vajpayee, she can play her audience like a fiddle.

She is given to spontaneous acts of charity and the fact that these are rarely publicised reinforces the notion that her heart is in the right place. By contrast, Rahul's outreach to have-nots — dinner with dalits and so forth — come across as a standard political ploy. Unlike him, she smiles often and to great effect. As a politician, she has a certain authenticity and where Rahul fumbles, makes faux pas and runs off at the mouth, she believes that when speaking, less is more.

Her candidness has often stumped the media. When her “sweetheart” land deal with an alleged business associate of Vadra came to light, she had no hesitation in issuing a statement affirming the transaction. Yes, she had purchased land in Faridabad from an individual and yes, she had re-sold it to the same individual four years later, at five times the price. The money was her own, the buyer had right of first refusal and the entire deal was by cheque. So what?

To dismiss her as a political novice would be a mistake. She has worked hard in the backrooms of the Congress in recent years, has contributed to decision-making and is familiar with the vicissitudes of the campaign trail. She is not an avid reader or number-cruncher like her brother, but she does know UP from the ground up and has interacted sufficiently with party workers, leaders and voters to be aware of the issues at stake. She is also said to be more accessible to party workers, during her campaigning forays.

That said, Priyanka will never second-guess, overrule or attempt to outshine Rahul. Political rivals may hope the siblings will pull in different directions, but their excellent rapport and seamless teamwork makes this unlikely. It also allays fears that Vadra will wield power by proxy.

On the other hand, Priyanka is known to have a temper and has no hesitation in putting even senior party leaders in their place. Where she chooses to draw the fine line between authoritative and authoritarian will impact both the party's cohesiveness and voter appeal. After all, Indira Gandhi is associated with an extreme form of authoritarianism.

As a dynast, Priyanka will have to tread carefully, particularly when dealing with regional allies. It is easy to be disarming as an outsider, but far harder when sitting at the negotiating table.

She would also do well to rein in her troops. Spokespersons Anand Sharma, Abhishek Manu Singhvi and Pawan Khera (who has worked closely with her in recent years), have taken to warning CBI, ED and Income Tax officials of retribution if they take action “on behalf of Modi”. Presumably, they mean the probes against Robert Vadra.

For a national party which accuses its rival of undermining institutions, threatening regulatory agencies sends the wrong message. There is a distinction between being a loyal wife and covering up possible wrong-doing. Priyanka took her cue from the 1960's hit 'Stand by your man/And show the world you love him'. Most citizens will empathize with her role as a wife, but equally, they will expect Priyanka-the-politician to say the law must take its course.

(Author is a senior journalist. Views are personal)