'Of course I'd like to support Bibi," the Likud MK said last week. "We all would, but can I really believe he's changed? As far as I can see, he's still making all the same mistakes." Binyamin Netanyahu has been making a comeback for the last six years; he's spent four times longer on coming back than he did on being absent from the political scene after losing the 1999 elections. But still, everyone is asking: "Has Bibi changed?" His detractors have already coined the phrase, "It's the same Bibi," while some of his old fans are asking, "Why does he have to change at all?" Ehud Barak has officially been away for six years - save for his half-hearted attempt in the 2005 Labor Party leadership primary - though he was never really absent. Through his loyalists in Labor, he continued to monitor the situation, every few months circulating rumors that his return was imminent and keeping his rivals off balance. Even the famously aloof Barak eventually realized that, except for a handful of diehards and a few bored political correspondents, no one was really awaiting his comeback. It took the unique combination of a disastrous war and an inexperienced defense minister at Labor's helm to create the one-off opportunity that enabled his return this week. Nobody really believes that men in their late 50s are capable of changing in any significant way, especially opinionated politicians who once made it to the top. What does change is the public's perception of them as crafted by their spin-doctors, press advisers and image consultants. But, ultimately, it depends a lot more on passing public moods and the changing taste of the media. Neither Barak nor Netanyahu thinks he was a bad prime minister; each can argue for hours about his successes, and explain how all the failures were those of underlings and an ignorant public. If it were up to either, each simply would have said, "I'm back" and expected us all to fall in line. Political ignominy has finally made both of them understand that the broad public - unjustly, they think - sees them in a rather different light. So they have to go through a humbling process of assuring everyone they talk to, whether in private meetings or on prime-time interviews, that Barak has changed and that this is the new Bibi. THE FIRST rule of making a comeback is to identify what the public and the media see as your weak spots. Barak used a low-key style to declare his primary campaign this week, just a beeper message to reporters, and a humble, handwritten letter to the party secretary-general. I wouldn't have liked to be the adviser who had to explain to him that the public doesn't want him back because they think he's a smug know-it-all. It probably took more than one adviser to hammer this home to him; but, finally, he seems to have accepted it - at least as a working assumption. That's why, instead of appearing on television and at large events, he's going to spend the next four months touring the country, meeting small groups and "listening." On May 28, if he lasts that long, we'll see if it did him any good. As for Netanyahu, he's been trying almost ever since he lost to Barak in 1999 to prove that he's not the panicky, impulsive and irresponsible leader most of the country believed him to be when they booted him out. He also drastically cut his media appearances, changed the tone of his speaking style (making it calmer and more measured), and chose his venues with care - anything to confer on him the status of an elder statesman. He tried to boost his consensus credentials by acting as Israel's international spokesman during the war this summer, despite being head of the opposition. And to his credit, over the last year or so he has seldom put a foot wrong. But he's been trying to do basically the same thing for almost six years, and last March, when he finally got his chance to lead the Likud in an election campaign, the party took the biggest mauling in its history. Now, all of a sudden, he's leading in the opinion polls. Well, not exactly "all of a sudden." There was a war, after all. IN THE end, as much as a politician might convince himself and the public that he's changed for the better, it's all about the timing - and nothing he does can alter that fact. Netanyahu made his changes at the turn of the millennium, but is only now leading in the polls; Barak would have willingly returned four years ago, but Labor seems only now prepared to try him again. The two biggest comebacks in Israeli politics were by Yitzhak Rabin and Ariel Sharon. Both managed to return after spending many years in the wilderness, becoming two of the most popular prime ministers in Israeli history, enjoying sufficient public support to carry out highly controversial policies. Both had to adapt themselves at an advanced age to new media environments, but fundamentally, they hadn't changed. However, both came along at a time when Israelis felt a deep and desperate need for a seasoned and confident leader, preferably a general of the old school, someone who had shown in the past that he knew how to deal with our neighbors. They were the right men for the moment. Just as was the case of Winston Churchill - who was a political failure for most of his career, only to be called to greatness by World War II - without that moment, they would have remained on the sidelines. Are we going through a period in which the nation prefers an experienced and known leader, even though it had rejected him in the past? The recent polls would indicate that the answer is yes. On the other hand, the public is fickle. Let us not forget that a mere nine months ago, these same polls were showing Kadima garnering 40 Knesset seats. What we are seeing now is Barak and Netanyahu each trying to seize the moment. What remains to be seen is just whose moment will come along at, well, the right moment.