First I should qualify the "many," since the mainstream media will not corroborate this assertion, either in Germany or in the US. You have to look a little deeper than the public pronouncements of Angela Merkel and Heiko Maas to find out what "Germans" think, just as US politicians and the MSM do not give an accurate picture of what "Americans" think. At least I hope not.
I could just say that everyone I know thinks Trump is a dangerous nut job, even my golf buddies -- though I have to keep telling them, "It's not just him!" But that might be misleading since my golf buddies consist mainly of my wife, who agrees with me most of the time, as long as I don't express myself too vehemently (which is also most of the time). Also, I have only been a German for three years, despite having lived here for 41. So I will defer to Albrecht Mueller, the publisher of NachDenkSeiten, one of my two main sources for news not only about Germany but also about the US and the rest of the world. (The other one is Telepolis.)
Mueller is a former SPD member of parliament and was the Planungschef ("Head of Planning") for Willy Brandt and Helmut Schmidt -- so, not nobody. His NachDenkSeiten website has an Alexa global ranking (last I checked) of 31,711, which ain't bad. (Compare washingtonpost.com 221, rt.com 314, wsws.org 43,479, consortiumnews.com 78,804, opednews.com 201,692.)
Mueller has been around a while (born in 1938) so when he says, as he did in a recent article, that "more and more" Germans no longer see the US as a friend, it means something, and probably applies even more to younger Germans, who have no personal recollections of post-war Germany.
"Friends of mine and I," Mueller says, "took a long time to lay aside the basic affection we had for the United States after the Second World War. We had learned from childhood that the Americans were first our liberators [from the Nazis], and then our protectors from the military and political power of the Soviets. Many of us wanted to go to America in our youth, preferably with the AFS, the American Field Service. In my hometown of Heidelberg, the Americans were omnipresent, contributing much to the post-war culture through the America House, for example, and jazz."
Those days are gone, and Mueller gives six reasons why Germans today, as the title of his article says, "and the majority of Europeans should get used to the idea that the USA is not our friend. It is an empire and treats us like a colony." I summarize:
1. "The US uses our country and Europe as a whole to wage its many wars around the world." Germans "share responsibility for the destruction of ancient cultures in the Near and Middle East and in Africa" and thus also become targets for terrorism.
2. "The US largely determines our foreign and security policy." Germany was instrumental in fostering European and East-West cooperation, and especially since 1990, has invested in political, cultural and economic ties with Russia. The USA and its Western allies, however, at the latest since the disappearance of their man Yeltsin, has deviated from this policy of cooperation. By participating in the war in Yugoslavia Germany made it clear that it would not pursue an independent foreign policy, and this has become even clearer today.
3. "The US has special rights as a former occupying power." The US still has troops, as well as nuclear weapons, in Germany and uses its German installations to fight wars all over the world. The best example is the coordination of drone attacks from the air base at Ramstein.
4. "US hedge funds and other financial institutions have undue influence on German companies." E.g., BlackRock.
5. "German and European markets are dominated by US de facto monopolies." E.g., Facebook, Microsoft, Twitter.
6. "US financial officials function as economic warriors by imposing sanctions, for example, against Russia and Iran." Mueller refers here to an an article in Die Zeit from 2014 about Daniel Glaser, who was then the Assistant Secretary for Terrorist Financing.
Mueller is an economist and presumably understands these last three points better than I do (which would not in itself be a great achievement), but he does not expatiate on them enough in this article for me to feel confident to say more. Still, though these points might be less self-evident than 1-3, it is clear that the US economy is the most potent in the world, a fact that no doubt best accounts for all six points. A current example is the dilemma Germany and other European countries find themselves in now, having to choose between business with the US and business with Iran, due to Trump's Iran treaty interruptus.
In short, as Mueller says, it will be difficult for Germany to grow a backbone and replicate the strategy of Ostpolitik developed under Willy Brandt in the 1950s and early 60s. The institutions responsible for this, writes Mueller, such as the Auswärtiges Amt (Federal Foreign Office) and the Stiftung Wissenschaft und Politik (German Institute for International and Security Affairs) are already in "transatlantic," i.e. US, hands, so other institutions need to take the initiative, such as the Friedrich Ebert Foundation, the Rosa Luxemburg Foundation, the Hans Böckler Foundation, and the Otto-Brenner-Stiftung. Mueller urges these foundations to finance a "group of experts to work out a plan for national security and foreign policy outside of the US imperial domain."
The problem with any plan, which Mueller does not mention, will be how to become independent of Big Brother without emulating the selfsame militaristic and nationalistic ways and means, for which, after all, Germany too has a solidly infamous history. The minority parties calling most clearly for rapprochement with Russia, for example, are Die Linke (The Left) and the AfD (Alternative for Germany), who are about as far apart otherwise (left and right, resp.) as you can get. The business-oriented FDP has also called for repealing or loosening the Russian sanctions, and there are similar opinions in the other parties, but the general tendency and official policy of the ruling CDU/SPD coalition is to toe Big Bro's line, at least until it hurts economically. Trump's policies are making that much harder, but that may prove to be a boon if they push Germany and Europe closer to the emancipation Mueller recommends.
Back to the question of how many is "many," it should be clear that political parties never represent public opinion accurately. This is less true in parliamentary systems, where minority parties participate in government and (therefore) receive at least some media attention, but what is reported outside the country generally does not reflect even this diversity. What the world hears from Germany, for example, comes from Merkel and Heiko Maas (CDU), not Andrea Nahles (SPD) or the leaders of the other four parliamentary parties.