The Times of Israel is reporting that Prime Minister Benjamin Netanyahu’s Likud party will merge with Avigdor Lieberman’s Israel Beiteinu party in advance of the January Knesset elections. There are four reasons for this.

First, as I wrote recently, in the 2009 elections Tzipi Livni’s Kadima party won the election by a single seat, but was unable to form a governing coalition, thereby enabling Netanyahu’s Likud, the runner-up, to form the current coalition. Polls have shown that such an outcome could repeat itself in January. However, if the Labor party continues its revival in the polls, it’s possible there would be enough seats to Likud’s left for Kadima to put together a governing coalition, especially if Aryeh Deri’s return to the Orthodox Shas party enables it to drain some votes from Likud, as polls have suggested it might.

Netanyahu wants to avoid any chance of this outcome, and the only way to do that is to win the election outright. Likud and Israel Beiteinu currently have 42 Knesset seats between them.

Second, the looming threat of a dominant Likud victory may ward off an attempted return by Ehud Olmert. Third, Yair Lapid’s new party, Yesh Atid, has finally made clear that it is a rightist party much in the mold of Israel Beiteinu—pro-two state solution but protective of major settlement blocs and a unified Jerusalem, with a secular political outlook. That revelation enables Netanyahu to absorb Israel Beiteinu and replace it with a nearly identical party, thus preserving the structure of the current governing coalition without making any major ideological changes or having to accommodate extraneous parties.

And fourth, demographics. Part of Likud’s success over the years was due to the fact that Mizrahi Jews–Jews from Arab lands, primarily, and their descendants–found a home in Likud. Labor tried clumsily to win them over about five years ago, but failed. Netanyahu is now hoping to secure the loyalty and partisan affiliation of Israel’s Russian immigrant community, which is over 1 million strong and represented by Lieberman and Israel Beiteinu.

Assuming the merger comes through and then the marriage withstands the test of time (and raucous, factional Israeli politics), what would Lieberman get out of this? When I profiled Lieberman and his impact on the Israeli political scene for COMMENTARY in the summer of 2011, I wrote the following:

There is one way in which Lieberman’s political career represents a new paradigm in Israeli politics: he is a heterodox political figure for the 21st century in Israel, a secular nationalist immigrant. His base is within the enormous Russian community, but, unlike previous ethnic politicians, he has interests and goals far more ambitious than bringing home the kosher bacon to his constituents through the use of government largesse. And unlike his predecessors in the ethnic political game, like the Moroccan populist David Levy or the religious Sephardi leader Aryeh Deri, he is playing on a far larger field.

Lieberman wants to be prime minister someday. And he happens to be almost a full decade younger than Netanyahu (Lieberman is only 54). It’s possible Lieberman–whose political instincts have always been vastly underestimated—sees the possibility of inheriting what would be the political party with the largest Knesset vote share since Yitzhak Rabin’s Labor party in 1992, if its electoral success continues at this rate.

But that is looking a bit far into the future. The truth is, such mergers are almost always unstable, and Lieberman has split from Likud before. But the Israeli left will take some encouragement from this if they believe they have spooked Netanyahu into thinking he could lose the January elections after all.