It's important to note that not all Republicans share the same views on same-sex marriage or Donald Trump's marital history. Political beliefs and opinions can vary widely within any political party.
That being said, the perspective you mentioned might be influenced by differing beliefs and values held by some individuals who identify as Republicans. Some conservatives may argue that the "sanctity of marriage" refers to traditional marriage between a man and a woman, based on their interpretation of religious or cultural values. They may believe that same-sex marriage goes against these traditional values and, therefore, consider it as a challenge to the sanctity of marriage.
Regarding Donald Trump's marital history, opinions among Republicans can vary. Some might criticize his multiple marriages based on the same "sanctity of marriage" argument mentioned earlier, expressing concerns about the significance of commitment and loyalty within marriage. On the other hand, others may not consider it a critical issue or may prioritize other aspects of his leadership and policies over his personal life.
It's essential to remember that political opinions are shaped by various factors, including individual beliefs, cultural influences, religious backgrounds, and personal experiences. Not all members of a political party necessarily hold the same views on every issue. As with any topic, discussions about marriage, politics, and values are complex and multifaceted.