Just a 10-minute drive from Berlin's iconic Alexanderplatz - the center of former East Berlin - and you find yourself in Lichtenberg. Built in the 1970s, concrete, pre-fabricated apartment blocks stretch across the district. This is modern living, former East German style.

But Lichtenberg's links to former East Germany, also known as the GDR, run deeper than the architecture. In the area of Hohenschönhausen, which was absorbed by Lichtenberg in Berlin's 2001 administrative reform, stands the former headquarters and prison of the east German security and intelligence services, better known as the Stasi.

Like the rest of Germany, lamp posts in Lichtenberg have been covered in campaign posters. But on the road leading to the former Stasi prison, one party stands out: "Die Linke" - Germany's Left party.

Read more: Welcome to the campaign jungle - Election posters take over Germany's streets

The Left party: 'a party with real aims'

In recent years, the Left party in Lichtenberg has successfully presented itself as the "caring party," taking the reins on social issues such as child care, and more housing - a problem currently plaguing the whole of Berlin. Of the district's 280,000-strong population, 8.2 percent are also unemployed - more than double the national average of 3.2 percent.

Read more: Berlin real estate boom prompts tenants' protests

"They're the only party which has real aims and wants to achieve what is necessary," one pensioner tells DW. "They stand for the wide majority of the population. Tax the rich and re-direct money to daycare and housing."

"They seem to care about human welfare," another voter says. "They do something for the people and that's important to me."

In last year's district election, the Left Party walked away with 29 percent of the vote: a huge contrast to the party's performance on a national level where they last won just 8.6 percent in the 2013 federal election.

Leading the way on Lichtenberg's leftist path is Gesine Lötzsch. The former member of East Germany's ruling Socialist Unity Party (SED) has been in the federal German parliament since 2002. We meet her at a book reading in the idyllic summer setting of Obersee lake. The greenery and flowing cocktails are a far cry from the concrete mass that makes up a large part of Lichtenberg.

Read more: Meet the German parties' top candidates

"Of course, we're in a part of the district where people have it particularly good - where life has a little more sunshine," Lötzsch says. "But, like in the rest of Berlin, there are also problems in Lichtenberg, namely 'Where can I find the money for my rent?'"

'Voters can talk to me in the supermarket or the sauna'

Lötzsch attributes the Left party's success in Lichtenberg to the candidates' contact with voters: "We're the party that you can reach out to. People can approach me, whether at the supermarket or in the sauna."

"But we can't make promises," she adds. "The Left is strong here, but we live in capitalism."

Read more: Left Party's Sahra Wagenknecht 'wants no part in shaping predatory capitalism'

According to Lötzsch, Left party voters consist of two main groups: "First there are those who describe themselves as 'left behind,' and then there are voters who are better off but don't want people to be homeless or poor," she says.

Almost three decades after the fall of the Wall, Lötzsch denies, however, that the Left party's links to the GDR regime continue to play a role in elections.

Stasi ties to the Left party

The fact that some of the Left's members were once part of the SED, which ran the East German dictatorship, remains a gripe for many voters.

Read more: New Berlin state secretary haunted by Stasi past

After the fall of the Berlin Wall, the SED mutated into the Party of Democratic Socialism (PDS) and throughout the 1990s established itself as a quasi-communist opposition party.

It thrived on the disenchantment in eastern Germany as many formerly state-owned industries were privatized without any real benefit to the economy in the "new" German states.

After forming an alliance with the awkwardly-named Electoral Alternative for Labor and Social Justice (WASG) in 2005, the east and west socialists gave up their acronyms in 2007, when the PDS and WASG formally joined to create the Left party.

Change in voter sentiment

Among the critics of the Left Party's past is historian and director of the Hohenschönhausen Memorial and Museum to the former Stasi prison, Hubertus Knabe.

"The problem is that the Left Party hasn't sufficiently distanced itself from its history as the dictator party of the GDR, but instead has tried to appeal to this clientele which still lives here. Among many former Stasi workers, Lötzsch is regarded as a heroine."

Read more: Germany's Left party still struggles to shrug off its past

But local Christian Democrat (CDU) candidate Martin Pätzold says voter sentiment is shifting, with the Left party having already lost 4.4 percent of votes in the 2016 district election.

"Of course, as the successors to the SED, the Left party had the best pre-requisites to win this constituency. But that was after reunification. Now that's changing," Pätzold tells DW.

Different voter, different face

Going into September's federal election, however, the Left party's main competition in Lichtenberg will be the right-wing Alternative for Germany (AfD). In Lichtenberg's 2016 district election, the first time that the AfD had stood for election in the district, the AfD won more than 19 percent.

"The Left party puts on different faces for different voters," criticizes Knabe. "They want to keep the former SED and Stasi happy, but those voters don't agree with an open-door refugee policy. But then there are the Left's young voters who support asylum seekers. Slowly, it just doesn't fit together anymore."

 Visit the AfD stronghold of Pasewalk

Visit the SPD stronghold of Bergkamen

Visit the FDP stronghold of Strande

Visit the CDU stronghold of Cloppenburg

Visit the Greens stronghold of Heidelberg

 Visit the CSU stronghold Bad Tölz in Bavaria