When Browning entered Parliament in 2011, there had been hopes his track record in campaigning for food safety would see him fill the role opened up by the retirement of the unflinching, uncompromising and hugely media-savvy Sue Kedgley, one of the party's greatest assets.
It was not to be. Browning has been close to invisible. Worse, he has given the impression that the Greens do not view the outbreak of Ebola with the sufficient degree of seriousness that the public demands of its politicians at such times.
This week's ridiculing of Browning was in sharp contrast to the reception accorded to the Greens' sole new MP, James Shaw.
National's Chris Finlayson - someone who does not make a habit of dishing out plaudits - tagged Shaw as a leader-in-waiting.
Finlayson sees Shaw as someone whose strategic thinking equates with that of Germany's Green Party. Such a comparison cuts to the very heart of the long-simmering debate among New Zealand's Greens as to where they should be positioning themselves on the political spectrum and whether they can ever go into coalition with National.
The Greens' unwillingness to do a deal with National has left them dependent on Labour. It was clear long before this year's election campaign that Labour would not secure enough votes to form a government, thereby making the Greens irrelevant to the outcome.
In contrast in Germany, relations between the Greens and the Christian Democratic Union, the National Party equivalent, have improved to the point that the two parties have held post-election negotiations at a federal level, though these have yet to bear fruit in the form of a coalition agreement. However, there have been two such deals struck at state level - in Hamburg in 2008 and in Hesse late last year.
There are several factors, however, which have made such accommodations possible in Germany but which are absent from New Zealand's current political climate.
Germany's Greens have been in Parliament for longer than New Zealand's Greens - since 1983 in the case of the former as against 1999 in their own right in the case of the latter.
Germany's Greens have had long experience of having governed at state and federal level with the Social Democrats, the Labour equivalent. They are thus well versed in the necessary skills of compromise. The New Zealand Greens have only limited negotiating experience.
The German Greens also had the huge advantage of a major, long-running issue on which they could hardly go wrong - closing the country's nuclear power stations.
The shrinking of the Social Democrats' share of the vote has also forced the German Greens to confront the previously unthinkable - a deal with the Christian Democrats.
This has been made more possible through the victory of the "realists" within the German Greens over the more principled "fundamentalists".
The New Zealand Greens have long avoided holding the equivalent debate within their party.
On one side are those who wish to push the party more towards the political centre to give it the option of doing deals with National, thereby increasing the party's leverage over both National and Labour.
There would be far more emphasis on lifting environmental standards and tackling climate change.
On the other side of the debate are those who prefer to give equal or higher priority to the party's social justice thrust by offering more help to the low-paid and beneficiaries and fighting child poverty.
In an astute speech last week, co-leader Metiria Turei sought to mollify both sides of what could potentially turn into a highly-divisive argument.
To those on the social justice side of the debate, she said it was not the Greens' job to move to the centre. It was to move the centre towards the Greens.
That has already happened under John Key's brand of "compassionate conservatism" and there must be doubt as to whether he can shift National any further to the left.
To appease the party's centrists, the Greens' leadership has written to the Prime Minister seeking talks on a possible memorandum of understanding to work together on areas of common interest in the same manner as the two parties did in 2008 by working together on insulating older houses at a discount rate.
Key's initial response was to raise the stakes by saying he is keeping the prospect of working with the Greens alive - but has hinted a quid pro quo would be the Greens supporting a National government in future.
Key has the advantage. While it does not take much to change the Government under MMP, Key will likely be able to call on New Zealand First and Colin Craig's Conservatives if needs be to maintain the hegemony of the centre-right after the next election.
The pressure is very much on Turei and Russel Norman, the Greens' other co-leader.
Deciding how to make things work for both parties is going to take some doing. What is clear is that status quo is not an option. The Greens may thus well inch towards the possibility of dealing post-election with National at some unspecified point in the future.
The key word is "inch".
There is going to be no rush on anyone's part.
