Both President Trump and President Obama used military force without informing Congress, or getting its approval. But the differences reveal more than the similarities.
An expert on Watergate says that today's House Republicans have taken precisely the opposite position than the GOP took in 1974 on the president's power to withhold documents from Congress.
The impeachment vote is the latest, and most extreme, example of a power struggle between the executive branch and Congress that has existed since George Washington was president.
Even if other parts of the federal government shut down, Congress could – and would have to – keep working. A legal scholar explains why and how that is possible.
President Trump refuses to provide information to lawmakers in the impeachment inquiry. But courts have been reluctant to take such cases for fear of upsetting the government's balance of power.
Both political parties are trying to draw analogies between the impeachment process and a criminal trial – for political reasons, not legal ones.
The United States is the only developed, democratic country that has a political culture of selling ambassadorships.
The first day of public impeachment testimony was defined, in part, by strongly worded statements from Representatives Adam Schiff and Devin Nunes.
The Hyde Amendment bans federal abortion funding for most people.
Democrats and Republicans are speaking about impeachment with dramatically different language. The winner of this frame war will succeed in shaping how Americans understand the impeachment inquiry.
A task force has been assembled in the US Senate to fight anti-Semitism. A specialist in Jewish-American history says the group has a big job ahead of it. Anti-Semitism has a long history in the US.
Since the 1940s, Congress has largely let the president make decisions, while members of the House and Senate endorse or condemn those actions from the sidelines.
A law professor explains political disclosure laws, how donors get around them – and what to do about it.
A bill making its way through the US Congress seeks to tighten scrutiny of Hong Kong's autonomy. But it will do little to resolve the situation.
The impeachment investigation of US president Donald Trump has formally started, but much has changed since 1974, when Richard Nixon was forced out of office.
Investigations often damage the president's approval rating, particularly if the inquiry drags on for a long time. But that may not matter to a historically unpopular president like Trump.
A quirk of mathematics gives voters in some small states, like Rhode Island and Nebraska, an extra edge over voters in other states. This happens not only in the US, but in other countries, too.
A former congressional staffer says withholding damning evidence from Congress and using civilians to carry out presidential or intelligence agency agendas links the Ukraine crisis to other scandals.
As the House mounts an impeachment investigation of President Trump, examples from Central and South America show that ousting an executive leader from office doesn't always have the intended effect.
The conflict between Congress and President Trump over his dealings with Ukraine's president is just the latest version of a long-running struggle for power between the two branches of government.