Until Thursday, Israel’s general elections were looking, forgive me, rather dull. Certainly a lot less interesting, and a lot easier to call, than the presidential vote across the pond next week.

Sure, all sorts of minor headline-making shifts were under way. A handsome (I’m told) ex-news anchor, Yair Lapid, was doing pretty well in the polls, on the basis of some common sense socioeconomic policies. Labor was relatively resurgent, under Shelly Yachimovich. Shas was buoyed by the return of charismatic ex-con Aryeh Deri. Kadima was heading for the edge of the cliff.

But there was no doubting who’d come out on top on January 22: Benjamin “Bibi” Netanyahu.

Then came the prime minister’s political bombshell: The Likud and Foreign Minister Avigdor Liberman’s Yisrael Beytenu had agreed to run on a joint ticket for the elections; or rather Netanyahu and Liberman had sewn up a secret deal to that effect.

It was easy to see what was in it for Liberman. At a stroke, he becomes Netanyahu’s heir apparent. And since he, rather than any genuine democratic process, gets to choose the Yisrael Beytenu ciphers who will constitute a full third of the names on the new joint party list, at a stroke he becomes the single most powerful figure in the two partnered parties. Yes, more powerful in terms of commanding MKs’ loyalties than Netanyahu himself, since the prime minister has far less influence over the Likud two thirds of that joint slate, which is selected by the 120,000 Likud party members.

Liberman has always wanted to be prime minister, and has gradually realized he can’t get there as head of what is still largely a Russian immigrant party. Now Netanyahu has cleared the path for him.

It’s been far harder to understand why Netanyahu thinks the new alliance is a good idea. For a start, in strengthening the politically skilled Liberman, he weakens himself. Second, he infuriates his own Likud’s most senior ministers — privately incandescent that Liberman has been catapulted above them in the leadership hierarchy.

Third, the alliance alienates Likud moderates — emblemized by Likud veteran Dan Meridor, the soft-spoken deputy PM and minister for the intelligence services who returned to the Likud benches in 2009 after a failed bid to build a strong centrist party a decade earlier. Meridor and a small but not entirely insignificant Likud grouping believe Israel’s vital interests require efforts to advance negotiations with the Palestinian Authority of Mahmoud Abbas — a man Liberman repeatedly describes as a “political terrorist.”

Fourth, the new partnership upsets Orthodox Likud members, for whom the ostensibly pork-eating Russians and their figurehead are anathema.

Fifth, it risks embittering the Likud’s mainstream Sephardi support, the rank-and-file whose parents first brought Menachem Begin’s Likud to power in 1977, not all of whom empathize with Liberman’s immigrant constituency, and who were already shocked by the resignation last week of the Likud’s most charismatic and successful Sephardi leader, Communications Minister Moshe Kahlon.

And sixth, it allows Israel’s critics to depict Netanyahu’s anticipated next government as extreme — characterized by Liberman’s “no hope of a peace deal with the Palestinians” approach, rather than the prime minister’s own “we want to sit down and talk peace, but the Palestinians keep setting pre-conditions.”

There are more negatives for Netanyahu too, but that’s enough to make the point, I think. And set against that big downside is the supposed big benefit: The alliance will guarantee that “Likud Beytenu,” “BiLi,” “LiBi,” or whatever they decide to call it will form the next government. Actually, it does nothing of the kind. Indeed, it might conceivably do the opposite.

The unfolding possible irony is that the Likud was certain — absolutely certain — to constitute the biggest party in the next Knesset, and Netanyahu was absolutely certain to be reelected as prime minister… until last Thursday. Never mind those bizarre polls purporting to suggest that an Ehud Olmert-led centrist alliance might somehow outstrip Netanyahu’s Likud. Olmert was highly unlikely to risk a political comeback, the egotistical leaders of the center-left were highly unlikely to defer to his leadership and coalesce under his command, and the vast masses of Israeli voters were highly unlikely to stream to vote for a new party headed by a former prime minister who — the Likud would have been reminding them in every election broadcast — has been convicted of one offense committed while in public office, is on trial for a second, and may face an appeal for his acquittals in corruption cases three and four.

Now, though, the picture has changed to Netanyahu’s acute potential detriment — and it is Netanyahu himself who changed it. Make no mistake, he’s still extremely likely to be reelected prime minister. And the Likud-Yisrael Beytenu alliance is still all-but certain to constitute the biggest party — although it’s not entirely clear how that will be judged, since the Biberman leadership duo is adamant that the parties are not formally merging, just running for parliament together.

But seeing the Likud dragged to the right by its association with Liberman, Labor’s leader Yachimovich and Kadima’s Shaul Mofaz immediately called for a center-left merger. The pressure is mounting on Lapid to join such an alliance. Former foreign minister Tzipi Livni may now deign to make a return. And Olmert, recognizing that Liberman’s newly prominent role rather muddies the legal waters in which he swims, is also far more likely to attempt a comeback. After all, it would be a lot harder for a Netanyahu-Liberman duo to assault an Olmert-led list over the former prime minister’s legal embroilments when Liberman has himself been under investigation in an extremely complex corruption case dating back to the late 1990s, a case that includes allegations of fraud and other serious suspicions and that, for all the attorney-general’s reported promises, is most unlikely to come to a head before polling day.

It remains highly improbable that all these clashing egos could bring themselves to cohabit a single political grouping, and still more improbable that they could defeat Biberman if they did. But it’s a little less unlikely today than it was before last Thursday.

At some stage in the fairly near future, Olmert and Livni are going to have to put aside their comeback calculations and actually make a decision.

In the interim, a certain veteran Israeli politician is probably wondering whether he should seize the moment.

It is safe to assume that Dan Meridor is not happy about Netanyahu’s new partnership with Liberman, a minister with whom he gets along well enough in the day-to-day but with whose worldview he rather disagrees. It is safe to assume, further, that Meridor’s already less than absolute regard for his prime minister and party leader has not been enhanced by the new alliance.

Looking across the spectrum, moreover, it can hardly fill Meridor with delight to see the center ground potentially dominated by the legally sullied Olmert, the failed Livni — so poorly regarded by her own Kadima members that they ousted her this year in favor of the risible Mofaz — and/or the unproven Lapid.

A politician who was concerned about where the country might be headed under Biberman, and had the ruthless political zeal to try to fill the centrist vacuum, would recognize that this is his moment. Dan Meridor may meet the first of those requirements. He has just a few days to show whether he meets the second.

Meridor, Israelis may recall, was immortalized in the 1990s by a Hartzufim (Spitting Image) puppet so timid and weak that his voice tailed off into silence in mid-sentence and his face faded clean away. The satirical caricature was potent because it seemed well-founded.

It’s highly improbable that Meridor, 65 and a very proud grandfather, has the energy and will to shatter that perception now. But he will never have a better opportunity. And he’d make our elections even more unexpectedly interesting.