I've studied Wagner's life and read several bios. He was not a misunderstood figure or someone who is misunderstood. The following Wikipedia piece is illustrative:
Under a pseudonym in the Neue Zeitschrift für Musik, Wagner published "Das Judenthum in der Musik" in 1850 (originally translated as "Judaism in Music", by which name it is still known, but better rendered as "Jewishness in Music.") The essay attacks Jewish contemporaries (and rivals) Felix Mendelssohn and Giacomo Meyerbeer, and accused "Jews" of being a harmful and alien element in German culture. Wagner stated the German people were repelled by Jews' alien appearance and behavior: "with all our speaking and writing in favour of the Jews' emancipation, we always felt instinctively repelled by any actual, operative contact with them." He argued that because "Jews" had no connection to the German spirit, Jewish musicians were only capable of producing shallow and artificial music. They therefore composed music to achieve popularity and, thereby, financial success, as opposed to creating genuine works of art.
The initial publication of the article attracted little attention, but Wagner wrote a self-justifying letter about it to Franz Liszt in 1851, claiming that his "long-suppressed resentment against this Jewish business" was "as necessary to me as gall is to the blood".[17] Wagner republished the pamphlet under his own name in 1869, with an extended introduction, leading to several public protests at the first performances of Die Meistersinger von Nürnberg. Wagner repeated similar views in later articles, such as "What is German?" (1878, but based on a draft written in the 1860s), and Cosima Wagner's diaries often recorded his comments about "Jews". Although many have argued that his aim was to promote the integration of Jews into society by suppressing their Jewishness, others have interpreted the final words of the 1850 pamphlet (suggesting the solution of an Untergang for the Jews, an ambiguous word, literally 'decline' or 'downfall' but which can also mean 'sinking' or 'going to a doom'[18]) as meaning that Wagner wished the Jewish people to be destroyed.[19]
Some biographers[20] have suggested that antisemitic stereotypes are also represented in Wagner's operas. The characters of Mime in the Ring, Sixtus Beckmesser in Die Meistersinger, and Klingsor in Parsifal are sometimes claimed as Jewish representations, though they are not explicitly identified as such in the libretto. Moreover, in all of Wagner's many writings about his works, there is no mention of an intention to caricature Jews in his operas; nor does any such notion appear in the diaries written by Cosima Wagner, which record his views on a daily basis over a period of eight years.
