It is important for Congress to impeach Trump, and not for the political reasons of favoring Democrats. The reason is that Trump is clearly taking pride in breaking or violating any and every norm that has been part of the presidency and the federal government since the time of George Washington. Perhaps the norm-breaking was inevitable. Other presidents have also broken norms, and in the process expanded the power of the office of president. But Trump has taken it to new levels. He, and his lawyers, are now taking the position that the president is exempt from oversight by Congress for anything. He is arguing that he can legally shoot someone in the middle of Fifth Avenue, and nothing will happen to him.
This is simply unacceptable, and it violates the entire principle of separation of powers and checks and balances that is an integral part of the U.S. Constitution.
It is important for Congress to take this opportunity to specify exactly what actions that Trump is taken that are impeachable offenses. The impeachable offenses have been poorly defined in the past, mostly because past presidents have done little that rises to the standard. Pres. Bill Clinton was impeached for one lie under oath. Other presidents weren't impeached even after actions that may have been far worse, like Pres. Reagan's Iran Contra scandal. But none of these presidents took the extreme efforts of Trump to get away with anything he can possibly get away with.
Congress also has to take measures to punish witnesses who refuse to testify, or testify falsely. It is clear that Trump will tell everyone not to testify. Without actual punishment to these people by Congress, this effort to obstruct justice will clearly continue as long as he can get away with it.
I just sent the following message to several members of Congress. At this point, it appears unlikely that Trump will be removed from office, because he seems to have the unrestricted support of Mitch McConnell and the Senate Republicans. Even so, it is important for the House to investigate Trump's actions and specify which of them, specifically, are impeachable. This is necessary for the survival of constitutional democracy.
"Please make every effort to impeach President Trump. Trump makes every effort to break norms of government. Congress has a duty to investigate which of his actions are impeachable offenses. Even if he is not removed from office, it is important to take the opportunity that he presents to specify which of his actions are impeachable. It is also important to enforce punishment on other members of the Trump Administration who refuse to testify truthfully to Congressional oversight."