Trump has not been conspiring with Russia. How do I know this? Because Russia has high standards regarding who they conspire with. Trump cannot hold a security clearance, which means he cannot be trusted to keep a secret. He is not a guy that you want involved in your clandestine operation.
Richard Nixon did not order the break-in at the Democratic Headquarters in the Watergate office building. Nixon was a savvy, experienced politician who knew these kinds of shenanigans would blow up in his face.
People working for Nixon carried out the Watergate break-in. People working for Donald Trump have been communicating with the Russian government.
Talking to Russians is not illegal. It's just that when you hold a security clearance, you have to disclose this to the government. If you don't disclose this information, you are breaking the law.
What got Nixon in trouble is that he tried to cover-up the crimes of his own men. If members of the Trump Administration have been breaking the law, and if Trump has tried to cover this up, then Trump should follow Nixon's example and resign.