It has nothing to do with his professional abilities, his political leanings or whether his appointment was technically in line with the rules. It has everything to do with the widespread perception that his appointment broke the rules.

Many have been quick to point to the EU's double standards in lecturing the Hungarian and Polish governments on the rule of law, while seeming to ignore its own procedures in appointing the EU's top civil servant. But the real damage isn't to the Commission's credibility towards Hungary's Fidesz or Poland's PiS. These governments would be pillorying the Commission whether they can rely on facts or not. The bigger problem is the impact on public opinion.

Public opinion matters to the Commission, especially in countries with populist authoritarians on the rise. Otherwise, it wouldn't have taken the unusual step of replying to Orban's 'Stop Brussels' campaign. Neither would Commission First Vice-President Frans Timmermans, when speaking about Poland, repeatedly stress that his disagreements are with the country's government, not its people. It seems that Timmermans has an endless supply of touching personal stories about the Polish people that he can call upon every time he needs to speak about his troubles with the Polish government. These stories are aimed at the public, not the government. Public opinion matters so much that Commissioners are now obliged to engage in a series of 'citizens dialogues' – town hall-style debates all over the EU.

The Commission is right to value public opinion. It has difficulty using the political and legal tools at its disposal to apply pressure to correct governments that are violating standards of democracy, the rule of law and fundamental rights. But even when it does use its powers, it is still dealing with democracies in Poland and Hungary, albeit with weakened standards. The retrogressive dismantling of protections for citizens in these countries cannot be reversed through international pressure alone. Pressure from the EU is necessary, but the lead rests with their populations.

The Commission cannot easily reach these populations. First, Fidesz and PiS have a tight grip on publicly owned media and, in Hungary at least, privately owned media is highly influenced by the government. Second, the Commission itself is incredibly inept at speaking directly to the public. Its communications style is usually boring, often technical, and sometimes plainly ill-advised. So much so that even when the Commission should be able to take credit for positive developments in Europe, this is often stolen from under its nose by national governments. Most citizens would be hard pressed to name more than the abolition of passport checks, passenger rights, roaming fees and Erasmus – proud achievements, but less than one per decade of the EU's existence.

When the Commission has these difficulties stacked against it, integrity matters all the more. In a fight for public opinion, how is the Commission supposed to convince the public that it is fighting for their freedoms if the people can't even trust it to play by its own rules?