As an American living in Europe I am very much aware of the difference in polling between mature democracies and the United States, all the more so when a political party floods the public market with false polls to dope the aggregators or creates false betting companies. There is simply no comparison between the legal safeguards in Europe, however flawed they may be, and the the lack of professionality and legal requirements in the States. After all, U.S. professional categories are regulated, such as doctors, lawyers and plumbers. Pollsters get along on reputation and arbitrarily doping their polls to have them align with other pollsters. First Amendment concerns protects bullshit.

Let me make an example: Italy. All electoral and political polls that are published in Italy must be published contemporarily on the state Agcom site with the complete methodology, all statistical analyses, response rates, method of interviewing, verbatim sequence of questions asked, etc., etc. Further it is forbidden to publish polls within two weeks of an election. Try to regulate polls stateside with those criteria.

In the end you have to rely on the reputation and track record of polling companies. For example, today the Des Moines Register/ Mediacom poll has Harris winning Iowa by 3 points while other polls have her losing by up to 10 points. The only problem is that Mediacom has an excellent reputation for being exact within 1 percentage point for the past 15 years. Why? because they stick to themselves and don't feed in arbitrary factors such as alignment with other polls that are heavily biased by slipshod polling companies that are in the act of flooding the polling market with pro-Trump polls.

Nor is Mediacom in the business of cutting corners to save money. They actually interviewed over 800 people. But in the end we are talking about reputation against fluff and clickbait, given that regulation only amounts to the professional honesty of single polling companies in the States.

The best approach is to ignore American polls.