研究迄今，李商隱在大中之前，基本上是與牛黨較接近。劉學鍇支持岑仲勉、傅璇琮之論點，認為王茂元並非李黨，又矛盾的只是將史書之論點，再加以解釋李商隱與王茂元之女結婚後，受到牛黨令狐綯之的排擠。另一方面，又支持傅璇琮之論點，認為會昌年，才開始瞭解李黨之政治作為，開始傾向李黨，並於大中年後，投靠李黨鄭亞後，受到牛黨令狐綯的壓抑。然而，李商隱為何在大中年間牛黨得勢，李黨失勢之際，卻又逆勢操作，跟隨李黨鄭亞前往桂管？如果照史書所言，李商隱是背恩之人，大中年間隨同鄭亞被牛黨貶謫，那李商隱應該背棄李黨，接近牛黨，才符合史書所言李商隱是背恩之人。但是，迄今卻又無法有合理的解釋，李商隱隨鄭亞入桂管幕，僅一年半左右，在大中十二年(858)病亡前，將近十年間，均與牛黨人士交流，這又該如何解釋？在此唯一關鍵問題，應該是一直與牛黨接近的李商隱，為何在大中元年與鄭亞接近，跟隨鄭亞前往桂管幕近一年半的時間？這才是研究李商隱與牛李黨爭問題的真正關鍵點。但是，綜觀李商隱的一生及其思想，其政治操守應是始終維持如一，對宦官之嫌惡也沒有改變，而且其所接觸的人士，也以牛黨居多，而且與令狐之友誼，也未曾改變。然而，李商隱為何與鄭亞接觸，若從李商隱的宗教思想來探討，應該可以得到一些啟發，鄭亞有可能不是李黨。

According the old studies, Shang-Yin Li always seems as a member of clique that had built by Sheng-Nu Niu. But after the year in 841A.D., Shang-Yin Li became close to the Clique that had built by Der-Yu Li. Because Shang-Yin Li was made friend with Ya Cheng.Intend to analyze the relations in Shang-Yin Li and the party struggles between the clique of “Niu” and “Li”. Maybe we must take a point on religious. Because during the life of Shang-Yin Li, he had never betray his friend Tao Ling-Hu that was a member joined the clique of “Niu”. By the way, Ya Cheng may had some probability not being take as a member of clique of “Li”.