Presidential historian Jon Meacham says former President Richard Nixon's Watergate scandal looks a bit like what's happening today.

Meacham, who has written biographies on Thomas Jefferson and eulogized former President George H. W. Bush earlier this month, brought some historical context to MSNBC's Morning Joe Tuesday morning. He described how Nixon's downfall coincided with an ongoing investigation and falling markets — much like what President Trump is seeing right now.

In the two-year fallout after 1972's Watergate break-in, Nixon started out claiming he was "not a crook" — something that "would've fit on Twitter," Meacham noted. From there, the economy began "souring," Meacham said, suggesting the markets could be a "barometer of what's going to happen to President Trump."

Then, Meacham brought the conversation into the present day by discussing Russian efforts to influence the 2016 election in favor of Trump. "If in fact Donald Trump knew about" these efforts, that raises the "live question" of whether these actions fit "the definition of treason in the Constitution," Meacham explained. It all makes for an "existential Constitutional crisis" in which a president could be an "agent of a foreign power," Meacham added.

Watch all of Meacham's conversation with MSNBC's Joe Scarborough below. Kathryn Krawczyk

Egyptian President Abdel Fattah Al Sisi has made it a priority to prevent political dissent since he took power after a military coup in 2013, just two years after the Arab Spring forced out former President Hosni Mubarak. But the lock down didn't hold Friday, as hundreds of people stepped out into the streets in Cairo and at least eight other cities throughout the country to protest alleged government corruption.

The demonstrators reportedly chanted slogans like "the people demand the fall of the regime" and "leave Sisi," which stirred memories of the 2011 movement.

Friday's protests were nowhere near those that occurred during the Arab spring, but just the fact they took place at all is significant — unauthorized protests are illegal in Egypt and after the 2013 coup, security forces killed more than 1,000 people and arrested tens of thousands of others, so those that participated did so at great risk, The Wall Street Journal reports. At least 56 people were arrested and police used tear gas to try to disperse the crowds.

The protests were a result of a call by exiled businessman Mohamed Ali, who accused Sisi of corruption. Ali, who said he worked as a building contractor for the army for 15 years, said he built five villas for Sisi's aides and a palace for the president in a military camp in Cairo. Tim O'Donnell

The reports that President Trump pushed his Ukrainian counterpart, Volodomyr Zelensky, to investigate former Vice President Joe Biden's son are not a great look for the commander-in-chief. But some people have pointed out that it's not the best news for Biden's presidential campaign, either.

Biden, who has maintained a steady lead in the Democratic primaries, now has to face the fact that his son, Hunter Biden, is "inextricably linked" to the story. That means the elder Biden will likely have to find a balance between trying to use Trump's potential folly to his political advantage and avoiding becoming part of a family scandal, The Washington Post reports.

He's already been going back and forth between attacking Trump and defending his son, the Post reports. None of this is really new — Hunter Biden's foreign business ties, which include a gas company in Ukraine that's been at the center of this situation, and personal exploits raised some eyebrows when his father first entered the presidential race. The threat of the story derailing Biden's bid seemed like it had subsided after a while, but now with Democrats likely to zero in on Trump's latest adventure as the House considers launching impeachment proceedings, it's back on the front page.

It also means that some of Biden's competitors in the primaries could question whether he's the right person to challenge Trump, the Post reports. "We're out there every day criticizing Trump and saying it's the most corrupt administration in the history of America," said Grant Woodard, a longtime Iowa Democratic consultant unaligned with a candidate. "It's going to be problematic for Biden to have to answer those questions about himself."

Others have similarly pointed out that they think ignoring the Biden family's role in the story — even if it's ultimately about Trump's interaction with Zelensky — is hypocritical. Read more at The Washington Post. Tim O'Donnell

There's something to be said for self-awareness — especially in the 2020 Democratic primaries.

Addisu Demissie, the campaign manager for Sen. Cory Booker (D-N.J.), suggested in a memo Saturday that the Democratic presidential candidate will bow out of the race if he doesn't raise $1.7 million in 10 days. The memo noted that only four campaigns have the funds to compete seriously for the nomination and Booker's is not currently among them. "Without a fundraising surge to close out this quarter, we do not see a legitimate long-term path forward," Demissie said.

Later, in a call with reporters, Demissie was even more forthright, answering in the affirmative when asked if Booker would drop out if the team fails to reach its goal. That will likely be tough, but Booker did raise $1.4 million at the end of the first quarter, so it's not inconceivable.

Booker's biggest problem when it comes to fundraising has been an inability to bring in small donations — just 21 percent of his presidential fundraising comes from donors who gave $200 or less, The Wall Street Journal reports. He also spent more than he raised in the second fundraising quarter which ended in June.

Still, Booker was able to qualify for the most recent debate in September, and there are several other candidates who trail him in the polls that will likely keep their campaigns going for far longer than Booker (if he can't come up with the money, of course.) Perhaps, it's really about getting out with your head held high. Read more at The Wall Street Journal. Tim O'Donnell

Rep. Joe Kennedy (D-Mass.) has entered the race.

Kennedy made the long-awaited announcement Saturday that he'll challenge Sen. Ed Markey (D-Mass.) for his seat in 2020. The 38-year-old grandson of the late Robert Kennedy said he plans to change Washington from the Senate. "Donald Trump has forced a reckoning without question," he said to a crowd in a community center in East Boston. "But to meet this moment it requires more than just beating him, it requires taking on a broken structure that allowed him to win in the first place."

Kennedy has an early lead on Markey in the polls, but Markey — who, like Kennedy, is considered a progressive — has a lot more institutional support, both at the state and national levels. The Democratic Senatorial Campaign Committee, Rep. Alexandria Ocasio-Cortez (D-N.Y.), and Sen. Elizabeth Warren (D-Mass.) all support the incumbent, for instance.

But Kennedy reportedly isn't too concerned about that. Instead, his campaign will likely focus more heavily on turning out new voters, especially immigrants and people of color — a strategy that worked well for Rep. Ayanna Pressley (D-Mass.) in 2018, Politico reports. His name, it turns out, doesn't seem to hurt, either. "People still care about the Kennedy name," said Scott Ferson, founder of Liberty Square Group, a strategic communications firm. "It's a very, very powerful legacy." Tim O'Donnell

Iran on Saturday sent veiled warnings to the United States and Saudi Arabia, shortly after Washington announced Friday that President Trump had approved a decision to deploy troops to Saudi Arabia following last week's strikes on Saudi oil facilities. Both the U.S. and Saudi Arabia allege that Iran was behind the attacks, but Tehran denies the accusations.

While U.S. Defense Secretary Mark Esper said the "modest" deployment would be "defensive in nature," Iran is apparently preparing for alternative scenarios and they seemingly want any country to think twice before launching any sort of military operation. "Be careful and make no mistake," General Hossein Salami, the chief of Iran's elite Islamic Revolutionary Guard Corps, said Saturday during a speech. He added that his forces are "ready for any scenario" and have carried out war exercises. "Our readiness to respond to any aggression is definitive," Salami said. "We will never allow a war to enter our land."

Salami went on to say that Iran "will pursue any aggressor" and "will continue until the full destruction of any aggressor." Salami was speaking generally, but there is little doubt the U.S. was the subject of his ire. Tim O'Donnell

The United States and El Salvador signed a "cooperative asylum agreement" Friday in what is seen as another attempt by the Trump administration to curb the flow of migrants from Central America coming into the U.S.

Few details about how the agreement will work or when it will go into effect were provided, but acting Homeland Security Secretary Kevin McAleenan said the pact "is one significant step forward" and that it will build on what the U.S. has "accomplished already" with neighboring Guatemala, which is trying to implement a "safe third country" agreement with the U.S. signed earlier this summer. El Salvador's Foreign Minister Alexandra Hill Tinoco told The Associated Press that the agreement could similarly lead to migrants from third countries obtaining refuge in El Salvador if they pass through on their way to the U.S., although most northern migration routes don't include the country.

Criticism was swift, with opponents arguing that El Salvador is not safe enough to serve as a refuge. "If this agreement goes into effect, the U.S. will be forcing the most vulnerable communities to seek safety in a country that is not equipped to protect its own citizens or provide economic opportunity," said Oscar Chacon, the executive director of Alianza Americas, a network of immigrant-led organizations. Read more at NPR and The Associated Press. Tim O'Donnell