One responsibility of Congress is oversight of the executive branch. What is oversight? Why is Congress doing less oversight today that it has in the past?

What will be an ideal response?

An ideal response will:
1, Explain that oversight involves monitoring how the executive branch carries out the provisions of the laws that Congress has passed and investigating possible abuses of power by executive branch officials, including the president.
2, Explain that oversight is primarily the province of the committees and subcommittees of Congress and is among Congress's most visible and dramatic roles, guided by the wishes of House and Senate leaders and the majority party caucus in each.
3, Note that in today's highly partisan times, whether oversight hearings take place and the relative vigor with which they are carried out depends increasingly on which party controls which branch of government.
4, Note that overall, the number of committee hearings has declined dramatically since 1980, probably because committee chairs have less power now, with less independence from the leadership on what they may do in committee. May mention that members now also spend more time raising money for their reelection campaigns.