Alexis Tsipras, now Greece’s prime minister and leader of the ruling party Syriza, is greeted by supporters during a protest in Athens in October 2014. (Lefteris Pitarakis/AP)

On Sept. 20, Greeks are once again going to the polls. Despite all the dogma, denunciations and drama of the last eight months, it looks as if chameleon-like Prime Minister Alexis Tsipras will again emerge triumphant.

[Greece just called new elections. Here’s the background you need to understand them.]

Apparently (see here and here) Tsipras is using the election to shore up his position within and beyond his own party, Syriza. ­

Tspiras has agreed to a painful and in many ways humiliating 86 billion euro ($96.8 billion) rescue package with Greece’s creditors, while remaining popular in the country at large. That is no mean feat. Tsipras was formerly a radical activist, but he appears to have learned – and learned quickly – how to play the real-world game of practical politics. That’s not true for most politicians on the left, as we and Michael Koβ found in our 2010 research on how parties to the left of the main social democratic actor performed in national governments.

Syriza and Tsipras came to power in January, and events have been dramatic since then. But despite Syriza’s radical message, its policy decisions have helped Greece both stay (at least for now) within the euro and potentially begin to rebuild its stricken economy. Drawing from our research, Dan Hough suggested that would be the case when he wrote here back in January.

Our research since 2010 has revealed two important things about ostensibly left-wing parties once they get into office. On the one hand, and often against their better judgments, they make compromises. The purity of opposition always burns bright in the hearts of party members, but the need to find solutions to challenging policy dilemmas forces many of them away from their radical roots. For instance, the Left Platform within Syriza, a forum for the most radical elements of the party, tried to prevent the government from agreeing to many of the most difficult reforms. But it lost. The need to compromise ultimately trumped the need to remain ideologically pure.

On the other hand, as Syriza illustrates, the experience of office can fundamentally change the way leaders make arguments. Alexis Tsipras, for example, now claims that the bailout deal he struck is the very best that was on offer — even though he called something very similar a plan to “humiliate” Greece. Stubborn creditors may have forced Syriza into compromises the party had actually encouraged Greeks to vote against in a referendum at the beginning of July, but he now explains that there was no alternative. As Tsipras now frames it, the choice was between the bailout that Syriza ultimately signed up for or a series of even worse policies that would have been agreed to by the still widely despised parties of the center-right and right.

[This is why the current euro zone plan for Greece is going to fail]

All this is consistent with what leftist parties have done elsewhere once in office. Alexis Tsipras has proven to be a genuinely skillful political operator, and he is now moving away from his hard-left roots. Syriza is becoming an office-seeking party rather than a programatically pure one.

That became apparent when 25 Syriza parliamentarians left to form their own political party, Popular Unity. But while they may have ideological purity on their side, they do not have the Greek people with them. Most Greeks are tired of fighting with the rest of Europe and are looking to move forward. Syriza’s deal is seen as helping them do that.

Leftist parties always find governing hard — but then, so do other parties. In other words, parties of the left behave in remarkably similar ways to parties of other stripes. Given what we’ve seen elsewhere, and as we noted in January, “Syriza is likely to move more in the direction of the mainstream, taking tough decisions and then struggling with the consequences.”

Tsipras might have threatened to press the self-destruct button on a number of occasions, but ultimately the attractions of power and the sheer doggedness of a party determined to defend itself and survive won out.

[What’s the matter with Greece? It can’t run the clean and effective government necessary for a healthy economy]

The trauma of taking over power has proven politically chastening for a significant part of Syriza’s membership, much as has happened elsewhere across Europe, where leftist parties often suffer disputes and divisions that lead to major internal crises. Whether the parties bounce back depends on the lessons that they draw from their experience in government. For some (such as the PCF in France), the lessons are that governing is simply too costly, bringing too few benefits and a great deal of internal discord. For others (such as the Vaensterpartiet in Sweden), being in government is seen as a positive good, even if it brings disappointments along the way.

Come September, Syriza will perform strongly. Tsipras’s skillful political maneuvering is likely to prevent the party from suffering election losses. While many Greeks view him with suspicion, a significant number will see him as the best of some bad options. In fact, Tsipras’s ability to present himself as the defender of Greek dignity and honor and his move toward the center will probably increase Syriza’s share of the vote, even with the new Popular Unity running to its left.

Syriza is likely to govern Greece for the foreseeable future. We do not yet know how it will do so when the austere realities of the bailout package kick in. For now, Tsipras and Syriza have survived intact. Whether that will still be true 12 months from now remains an open question.

Dan Hough is a professor of politics and director of the Sussex Centre for the Study of Corruption (SCSC) at the University of Sussex. Jonathan Olsen is professor of government at Texas Woman’s University.