[SauronOfMordor]

the Karaites are a lot closer to Judaism than Reform, Reconstructionist, or Chabad Judaism is.

The Orthodox rabbis will keep company with a Reform rabbi, because the Reform rabbi does not deny the Talmud, he simply does not think it is as applicable to the modern world as it used to be. This does not undermine the authority of the Orthodox rabbi

The Karaites, in rejecting the Talmud, reject the authority of the rabbis

[ChicagoHebrew]

Nonsense. Reform Judaism rejects the divine authorship of the Bible, and rejects the divine authorship of any Oral Law. Reform rejects all of Halacha (Jewish law, a combination of Torah law, Talmud law, and Rabbinic law), and ergo rejects the authority of the Rabbis.

Karaism, which rejects only the Oral Law and rabbinic halacha, is much closer to Orthodox Judaism than Reform is.