Countries that rank far higher than the United States on The Economist’s Democracy Index bar paid political ads because they view them as propaganda. Those countries also provide dramatically more support for public media to ensure a broader range of voices and deeper political analysis.
Immediately, some people will question the standards used by The Economist, a British newsweekly identified with Toryism. Many Americans believe that unlimited spending on political ads is the only defense against a monopolization of the media by spokesmen for the incumbent government or the "political class." From this point of view, the power to buy ads is the only effective way that concerned citizens from outside the political class can get their message out to the masses. In Britain itself, the law sees things differently. While Americans view paid advertising as a necessary corrective to an unbalanced discourse dominated by the political class, the British see paid advertising itself as a distortion of political discourse in favor of those who can afford to buy the most ads. I don't know where the U.K ranks on the Economist index, since you have to register with the magazine to see the stats, but that country has a longstanding, comprehensive ban on paid political advertising that was challenged earlier this year by the European Court of Human Rights.
At issue was the desire of an animal-rights group, Animal Defenders International, to run a 30-second ad on British commercial TV. The group went before the international body to argue that the British ban violated the would-be advertisers' human rights, particularly their freedom of expression while imparting information of public interest. The British position was that there could be no exceptions to their ban if they hoped to keep Big Money out of politics. In the meantime, since the ban doesn't cover the Internet, people could see the disputed spot on YouTube at minimal cost to everyone involved. For that reason, ADI argued that the ban on TV advertising was obsolete and irrational. They also argued for a narrower definition of political advertising, suggesting that the ban, if at all permissible, should apply only to electioneering ads advocating the election or defeat of candidates for office. Americans are familiar with this line of argument, which resulted in the proliferation here of 501(c)(4) organizations that are transparently partisan without engaging in specific electioneering.
By a 9-8 vote, the human-rights court upheld the British ban. You can read a news summary (and an interesting comment thread) here, and the opinion of the court (with dissents) here. Precisely because of the growth of social media, the majority determined that the ban on TV advertising did not deprive ADI of its freedom of expression, while observing that the group was not banned from interviews or panel discussions in the British news media. The dissenters speak in terms most Americans know and many agree with:
The general ban on “political” advertisements is problematic not only because, as already indicated, it borders upon prior restraint, but in view of the very doubt as to the usefulness for its purpose – there seems to be an inherent contradiction in a viable democracy safeguarded by broadcasting restrictions. Indeed, in our view, the general ban on “political” advertisements appears to be an inappropriately assumed positive duty of the State to enable people to impart and receive information. It is based on the view that powerful groups will invariably hamper the receipt of information by a one-sided information overload. Promoting a right where it cannot be effective without additional State action is, according to our jurisprudence, appropriate, but is not a generally accepted primary ground for rights restriction. There is a risk that by developing the notion of positive obligations to protect the rights under Articles 8 to11, and especially in the context of Articles 9 to11, one can lose sight of the fundamental negative obligation of the State to abstain from interfering.... Entirely and permanently closing off the most important medium of communication to any and all advertised messages about the conduct of public affairs is a harsher constriction of freedom than is necessary in a democratic society. Freedom of expression is based on the assumption that the speakers, not the Government, know best what they want to say and how to say it. Ideas can compete only where the speaker is in a position to determine, within the limits recognized by the Convention, which form of imparting ideas serves best the message.... There can be no robust democracy through benevolent silencing of all voices (except those of the political parties) and providing access only through programming. A robust democracy is not helped by well‑intentioned paternalism.
The narrow margin in the court only assures that the debate will continue in Europe as it persists in the U.S. The dissenters seem to share the American assumption that the political process can be distorted or hampered only by state power, when the universal understanding of the phrase "buy an election" suggests otherwise. Civil libertarians worry that governments may forbid certain things from being said, or certain people from speaking, yet are rarely as much concerned with the content of what might be said. In simpler terms, the danger of censorship is usually seen as greater than the danger of lying; the possibility that a free participant in political discourse could distort the discourse is rarely recognized, or else those concerned about the possibility are chided for "paternalism." Admittedly, political debates often (if not always) mix facts and values, so that many claims, e.g. about the future moral consequences of controversial policies, are arguably unfalsifiable and immune to the "lie" label. But it seems naive, after the 20th century, to be unconcerned about the dangers of propaganda, or to assume that propaganda is only effective when backed by state power. To the extent that any nation is a democracy, it will be impossible to eliminate unreason from political discourse. But ways may be available to minimize its effects, and the cures need not be assumed worse than the disease.