Tzipi Livni's days as Kadima's leader are numbered, regardless of whether she takes her party into Prime Minister Binyamin Netanyahu's government or not. The only surprise is that it has taken this long for her bubble to burst, and the major question remaining is whether Netanyahu will be successful in his cynical, though legitimate attempt to destroy Kadima. Livni's position is untenable. If she accepts Netanyahu's offer and enters his government in return for a handful of minister-without-portfolio positions, she will be admitting she made a colossal error of judgment when she refused to join forces with Netanyahu at the beginning of his term. Back then, Netanyahu was offering her half the kingdom and at least two of the top three ministerial portfolios - the Foreign Ministry for her and Defense for Shaul Mofaz. It was only Livni's insistence that Netanyahu agree on rotating the premiership with her that spiked the deal - not any major ideological chasm between her and the Likud leader. That stubbornness has come back to haunt her as she faces the humbling prospect of joining Netanyahu's government as very much the junior partner, despite heading the largest party in the Knesset. It's not as if she can argue today that Kadima's joining the coalition will help moderate its stance, because Labor has already cashed in on that claim. With Netanyahu signing up, at least verbally, to the notion of two states for two peoples and declaring a 10-month construction freeze in the West Bank, there is little more for Kadima to demand given the Palestinian refusal to resume negotiations. On the other hand, if Kadima remains in opposition, Livni will be left with a dispirited faction, some of whose members have openly called for joining the government and who remain ripe for the Likud's picking. Meanwhile Mofaz, scenting blood and keen to revenge his narrow and questionable defeat in the previous Kadima leadership election, will not hesitate to reissue his challenge. THIS TIME around, Mofaz will be in a much stronger position, for there is a limit to the number of Livni failures Kadima members can be expected to stomach. Let's not forget, Livni has twice failed to establish a government despite enjoying the advantage of Kadima's parliamentary strength - the first time when she replaced outgoing prime minister Ehud Olmert in the previous Knesset and secondly after the latest Knesset elections nine months ago, even though Kadima then polled one more seat than the Likud. Moreover, Livni has failed to lead while in opposition. The only Kadima initiative in this Knesset has come from Mofaz, and his plan for the establishment of a Palestinian state within temporary borders. Livni has hoisted no flag for her supporters to follow, and it is unclear exactly what Kadima stands for these days. Heading the opposition when the governing coalition is so large and so wide-ranging is a difficult task, but Livni has made no headway whatsoever in denting the government's omnipotence. Kadima was founded because of an idea: Ariel Sharon's belated understanding that Israel needed to end the occupation and create, unilaterally if necessary, new borders for the country that would ensure its survival as a Jewish and democratic state. Helped by Labor renegade Haim Ramon, who was motivated by a deep desire to destroy his former party, Sharon created a new party attractive to voters on the center and center-left of the political map. As Yossi Beilin has pointed out, under Olmert's leadership Kadima moved further leftward, seeking a full, final-status agreement with the Palestinians, something Sharon himself never envisaged. In the 2009 elections, the votes for Kadima came from former Labor, Shinui and Meretz voters, but the majority of the Knesset members on the Kadima list have their roots in the Likud. Now that Netanyahu has crossed the Rubicon in terms of accepting the idea of a Palestinian state, there is little holding them back from returning to the Likud and abandoning Kadima if Livni turns down Netanyahu. IT WAS always said of Kadima that this was not a party built for opposition. Without any political past to draw on and a dictatorial party constitution that prevents an open and honest discussion of the party's policies and leadership, Kadima has found it difficult to shape itself to life outside of the corridors of power. Furthermore, Livni is not a "people person." She neglected her rank-and-files MKs, a dangerous mistake given the amount of spare time opposition MKs have at their disposal for plotting, and deliberately snubbed Mofaz when he raised his diplomatic initiative. This character trait of Livni's is not new; when she was foreign minister all her close advisers resigned, one after another, due to the difficulties of working with her. Netanyahu is well aware of all this and hence his move first of all to entice a significant number of Kadima MKs to break away from the party and then his offer to Livni. The prime minister is not being sincere when he says the current state of affairs demands Kadima join the government; his present coalition is wide and stable enough to see him through any number of political crises. The 10-month settlement freeze has bought Labor's continued membership in the government, Shas has no reason to cause Netanyahu any problems and Israel Beiteinu is more concerned over the possibility of Avigdor Lieberman's indictment than its failure to advance any elements of its manifesto. Netanyahu is simply making mischief, and he is able to do so because Livni only became Kadima leader because she was the antithesis of Ehud Olmert in terms of her personal behavior and not because of any personal accomplishments. But as she and Kadima have learned, it takes more to head a political party than not smoking cigars or enjoying first-class travel at somebody else's expense. The writer is a former editor-in-chief of The Jerusalem Post.