It is not new that Shaul Mofaz is capable of the odd flip-flop. But what happened in the very small hours of Tuesday morning was a reversal by Mofaz that absolutely nobody saw coming.

A former defense minister and deputy prime minister, Mofaz was tired of being in the opposition. Pundits had seen that even before he beat Tzipi Livni in the Kadima primaries in March. Many political analysts suspected the 63-year-old of being far more willing than Livni to join a Netanyahu-led government, but he kept on denying it.

“I intend to replace Netanyahu,” he had told The New York Times after his landslide victory over Livni, who was punished by Kadima voters for being steadfast in her refusal to join the government at any cost. “I will not join his government,” Mofaz had pledged.

Just a few days ago, Mofaz had spoken out in support of former Shin Bet head Yuval Diskin, who had launched a bitter attack against Prime Minister Benjamin Netanyahu and Defense Minister Ehud Barak, saying he had no confidence in their leadership. Mofaz said that “Diskin’s words are a warning sign to be taken seriously.”

Back in 2005, when Ariel Sharon invited Mofaz to leave the Likud — of which he had been a member since 2002 — and join the newly founded Kadima, Mofaz showed that he was very flexible when it comes to keeping commitments. At first Mofaz declined Sharon’s offer, famously saying that “you do not leave your home.” But less than a month later, when it was clear that he had no chance of becoming the head of Likud, as he had hoped, he did leave home and joined Kadima.

In 2012, Mofaz is not switching parties, but his sudden move smacks of political opportunism just like the one in 2005.

Mofaz clearly thirsts for political power. As vice prime minister, he will fill in for Netanyahu and sit in all important ministerial committees. He could never understand why Livni passed twice on the opportunity to take government responsibility. And when he won the helm of Kadima earlier this year and then realized that the party could emerge too weak to be interesting to Netanyahu, he expediently joined forces with the man he had attacked just days earlier.

The Kadima members chose to either forget or ignore his flexibility when they made him head of their party. But they will ask him — and he will ask himself — if Tuesday’s deal is worthwhile in the medium-term.

Come election time, will voters choose a man who seems prepared to go to very great lengths just to be in the government?

Election time, now, of course, will not be on September 4, as we all thought. But the day is also not too far in the future. As of Tuesday morning, the next Knesset elections are scheduled for October 2013.

That gives incoming Vice Prime Minister Mofaz — who will now enter the history books as the man with the shortest period as opposition leader – 15 months to make an impressive enough impact to help voters forget his flip-flopping.