The PDS, the socialist party evolved from the former communist East German SED is one main part of that new "Linkspartei".
I wouldn´t call them a "socially conservative group in the East".
Oh, and just to illustrate the point... First a short VERY simplified explanation. Germany has a mixture of a proportional and representive election system. Half of the elected representatives are directly elected in voting districts. Simple majority vote. The other half gets elected according to the percentage of the vote. VERY simplified your party gets 10% of the votes in a state, you get 10% of the elected representatives of that state. So in a small party being first on that state "list" is good for your chances to get actually elected.
Berlin: First three places on the list going to former PDS members.
Bavaria:!!! Second, third, fourth place (according to n-tv) going to former PDS members.
And why? Because of German election laws (source n-tv). (Simply put founding a new party takes time.)
"Only a few weeks ago it looked as though the (mostly East German) PDS might not get elected into the new German parliament. Then the party "renamed" itself into "Linkspartei.PDS". The public probably thought that the fusion with the (mostly West German) WASG party was already a done deal.
That fusion though hasn´t happened yet. Only in about two years time PDS and WASG plan to fusion into a joint party. In this election WASG members like former SPD leader Oskar Lafointaine are joining PDS lists. Because of resentments in the West against the name "PDS", WASG politicians insisted in a renaming of the PDS.
What initially looked like blackmail by the WASG is now considered a huge boon for the PDS: Election laws help them to dominate and control the order of nominated candidates. The left-wing daily newspaper "taz" commented that with a cite by (East German communist party leader) Walter Ulbricht from 1945: "Everything should look democratic, but we must control everything." "
Party A gets an extra 5 seats from its list to make it have 40 in total. Party B gets 20 seats to give it 35 Party C gets 15 Party D gets 10 In sum a perfectly proportional result.
Things get more complicated in special cases where a party gets more seats than it should, for example like the SPD in the last elections in some of the Eastern Laender where it got all the direct seats with less than 50% of the vote. Those are known as 'overhang' seats and the party that gets them gets to keep them but the other parties still get the number they deserve. Hope that made sense.
Also you need at least 5% of the national vote or a certain number of direct seats to get party list seats. The PDS failed to do so last time and ended up with just its 2 or 3 direct seats. These 'wasted' votes are divied up between the other parties.
Why does election law favor this? Because, AFAIK, German law prohibits parties from forming joint lists. Since the PDS and the WASG are not really merged, you can't just put only WASG people on a PDS list. These lists are likely to be declared invalid. Thus the lists are heavily PDS dominated.
BTW, regarding overhand votes, they actually favor the party who gets them, because these members are added to the Bundestag, AFTER the parties have received the share of seats according to the poll. This favors big parties, because small parties are unlikely to get direct seats at all and thus they have no chance for overhang votes.
Overhang votes are a flaw in the German election system, that clearly needs to be fixed. But since they are so few (and since they favor big parties) , there's not a great push towards change.
Basically, extrapolating from past elections: The "PDS" alone would get something like 30+ percent in the five East German states. And something like 2-4 "direct seats" in East Germany. Probably enough to give them "some" presence in the new German parliament. BUT not a deciding influence!
In West Germany though, the "PDS" on its own would get around 2%. A marginal party in the whole of Germany. That by the way is the same point, the main speaker of the "PDS" Gregor Gysi is telling his "own" PDS state groups now.
By associating the "PDS" with the mainly West German "WASG" party and using the new name "Linkspartei" the "PDS" party avoids that "obstacle". It´s much easier for West Germans psychologically to vote for a new "Linkspartei" than to vote for the formerly communist "PDS".
While at the same time, due to current German election laws, the "PDS" remains in control of the nominating process. (In Germany party members or party committees decide on nominating parliament candidates. We don´t have "primaries" or elections by voters to decide on nominees. So in a new "list" a few hundreds or thousands of dedicated party members in a state could decide the placement of all the candidates on the list.)
I do admit that I didn´t research the nominating lists for each state. I did look for some but I found only newspaper articles about Berlin and Bavaria for now. I could understand Berlin, the "PDS" is really strong in Eastern Berlin. So giving the first three list places to "PDS" members might make sense.
But Bavaria? Simply put, give me a break! No candidate of the "Linkspartei" will get a direct seat there. If a member will get elected there, it will be over the joint state list.
Three out of the first four list candidates in Bavaria are "PDS" candidates. THAT is simply unrealistic! There is no way that the "PDS" is four times stronger than the "WASG" in a West German state! Totally unrealistic even if the new "Linkspartei" polls at anything as their 10+ percentage right now.
THAT seems to indicate that the "PDS" is using its advantage as the "listed" party to place as many of their own candidates on the list while using the name "Linkspartei" to their advantage. And screwing the "WASG" in the process....