The only time I've witnessed what I would consider to be a correct and accurate use of the threat of impeachment, was back during the Watergate mess. In that case, the problematic concerns about the President were so fundamental to the function of the country, that no other business COULD proceed, without addressing them.

The impeachment of Clinton was definitely a petty partisan effort to overturn a vote that the opposition resented, and so far, I have not seen enough evidence to support anything other than the same kind of partisan effort against Trump.

In the case of Clinton, the possible "crime," was as close to nonsense as I've seen (lying about cheating on a spouse is NOT a "high crime or misdemeanor"). In the case of the accusations against Trump, those are much more serious, but again, none of the evidence presented so far, supports anything more than possible prosecution of several of his appointees and relatives, for corruption.

However, the "threat" of impeachment against Trump, is NOT AT ALL impeding either the President, or Congress. A couple of subcommittees are spending a relatively small amount of time reviewing evidence collected by other people. Other than that, it's all fluff in the mass media. The members of Congress who could be acting on the other issues of the day, are not involved, and so can accomplish whatever they like, provided they can get enough Republicans to agree.

The divisions within the GOP, especially between the party and the President on POLICY and on Presidential actions, is where the action to see to the interests of the United States is being flummoxed. The whole deal with impeachment hasn't affected anything.