The past week and a half has been dizzy with developments:

Believe it or not, Congress can help contextualize this. Its main function is to oversee the federal government, which means lawmakers are in a position to get clarity from the executive branch that can help the rest of us better understand what's really happening to the Trump administration right now.

Here are five questions Congress can — and should — answer about Trump and Russia:

1) Did Trump do anything illegal in his conversations with Comey?

Then-FBI Director James B. Comey prepares to testify before Congress in July. (Andrew Harrer/Bloomberg News)

This is not a question Congress can answer right away. But after news broke this week that Comey had put to paper that the president asked him to drop an FBI investigation of Michael Flynn, it's a question Congress is trying to answer.

Making the matter more urgent: On Friday, the New York Times reported Trump told Russian diplomats that firing Comey took “great pressure” off the president. “I just fired the head of the FBI,” Trump said, according to notes of the meeting read to the Times by an American official. “I faced great pressure because of Russia. That's taken off.”

Several committees in Congress have already requested documentation of Comey's notes about his conversations with Trump. Many of those committees have asked Comey to testify, and late Friday, leaders of the Senate Intelligence Committee said Comey will appear before the panel publicly sometime after Memorial Day. Depending on what Comey says, it could be his word against Trump's.

And Congress will have to decide whom to believe. Stay tuned on this.

2) Can Deputy Attorney General Rod J. Rosenstein's judgment be trusted?

Deputy Attorney General Rod J. Rosenstein arrives to brief the Senate on May 18 (Jonathan Ernst/Reuters)

Rosenstein is at the center of Washington's most independent investigation into Russia and Trump ties.

He appointed former FBI director Robert S. Mueller III to a job giving him wide latitude to investigate whatever and whomever he wants under the umbrella of Russia and Trump. But ultimately, Mueller is answerable to the Justice Department. And since Attorney General Jeff Sessions has recused himself from all Russia investigations, Mueller is answerable to Rosenstein.

Except Rosenstein's reputation may have taken a hit in all this.

At least two Democratic senators said Rosenstein told them this week that he knew Trump was going to fire Comey when he wrote a hasty memo outlining what he sees as Comey's faults.

But Rosenstein also threatened to resign if Trump's White House kept using his memo — which never explicitly advocated for firing Comey — as the linchpin for doing Comey in.

So, if Rosenstein didn't want to be the torpedo that sunk a widely respected FBI director, why did he assemble one knowing Trump was going to fire Comey? And what does writing the memo anyway say about Rosenstein's allegiances?

Capitol Hill hasn't come to any consensus about whether to give Rosenstein the benefit of the doubt.

“I don't believe anyone in any way directed him,” said Rep. Darrell Issa (R-Calif.), “but in fact he wrote the memo.”

3) Is the special counsel a “witch hunt”?

The president thinks so:

Republicans in Congress aren't so sure.

Republicans are in the awkward position of welcoming an investigation they never wanted while trying to stay on good terms with a president who really, really doesn't want it.

“We're a nation of laws,” was all Sen. Marco Rubio (R-Fla.) would say when asked by reporters Thursday to weigh in on Trump's “witch hunt” characterization. “I have full confidence he will conduct an independent, thorough and fair investigation.”

Now that we know the FBI is targeting a senior White House adviser, Republicans will have to decide whether to keep balancing this tightrope or whether to fully support the independent investigations going on into ties between Russia and the president.

4) How will Congress's Russia investigations change?

Reporters surround the top Democrat on the Senate Intelligence Committee, Sen. Mark R. Warner (D-Va.), in May. (Chip Somodevilla/Getty Images)

Congress has two committees — the House and Senate intelligence committees — that are taking the lead on investigating Trump-Russia connections in Congress.

But the special counsel's investigation arguably takes priority over all that.

Sen. Lindsey Graham (R-S.C.) said he got the indication from Rosenstein that the special counsel will essentially put Congress's investigations “on the back burner,” because Mueller will have priority over key documents and witnesses.

Rep. Elijah Cummings (D-Md.), the top Democrat on the House Oversight Committee, said maybe Congress's role will have to change from finding out what happened to finding a way to make sure Russian meddling does not happen again.

“I am convinced that the Congress has a very significant role,” Cummings told reporters Friday.

Congress just has yet to define it.

5) Who will be the new FBI director?

FBI headquarters. (Marvin Joseph /The Washington Post)

A very important question just got even more massively important now that the FBI's investigation has found its way into the White House. Trump gets to nominate his replacement for Comey, but the Senate has to approve it. Former senator Joe Lieberman, who served as both a Democrat and independent, is apparently the top contender.

Democrats say any politician is a hard no because the FBI needs someone aggressively nonpartisan at this moment in time.

“I think it's a mistake to nominate anyone who's running for office,” said Sen. Claire McCaskill (D-Mo.). If Trump does appoint someone with a political past, Senate Democrats are considering what leverage they have to stop it.

(A president's nominees now require only a majority vote in the Senate, and Republicans have a slim one. But Democrats could filibuster other legislation.)

Also worth asking: Does news of the escalated FBI investigation change the standards of what makes a “good” FBI director for Republicans?