South Bend, Indiana, Mayor Pete Buttigieg and Sen. Amy Klobuchar (D-Minn.) are both receiving a fair amount of praise for their proactive approaches during Tuesday evening's Democratic presidential primary debate in Westerville, Ohio. That aggressiveness, several analysts concur, seems to have resulted from the sense that former Vice President Joe Biden's standing as the leading moderate candidate was vulnerable. Subsequently, both Buttigieg and Klobuchar felt like they had a chance to seize that territory — in fact, Buttigieg came across as so moderate, even some conservatives were touting his performance on stage.

The candidates were particularly focused on going after Sen. Elizabeth Warren (D-Mass.), who they likely consider the frontrunner, and her support for Medicare-for-all. Klobuchar called it a "pipe dream," while Buttigieg criticized her vague response to a question about how she planned on funding the proposal. He kept that up the following morning, as well.

Their decision to forego running to the left of Biden during the debate indicates their campaigns believe there is still a vibrant centrist voting bloc in the party, and that Biden's failures are more related to his performance than ideology. But, at the same time, there appears to be a sense of urgency from Klobuchar and Buttigieg, who may be realizing they can't just wait around for Biden's campaign to fizzle out. Tim O'Donnell

Rep. Eric Swalwell (D-Calif.) probably made some important points on Monday night's Hardball about President Trump's alleged bribery, high crimes, and/or misdemeanors through subverting U.S. law and government apparatuses in service of his personal political benefit. But nobody will remember his point because in the middle of his interview with Chris Matthews, this happened:

Did Swalwell really submit to a massive attack of flatulence on live national television that was so loud his lapel microphone picked it up? He says no.

Hardball briefly toyed with turning the entire kerfuffle into an audio version of he-who-smelt-it-dealt-it.

But cooler minds prevailed. Or something.

Luckily, as we all know, conspiracy theorists are often persuaded by plausible explanations. Peter Weber

Hoping to end speculation about President Trump's surprise weekend visit to Walter Reed Medical Center, the White House released a memo on Monday night written by Trump's physician, who said the "trip was kept off the record" due to "scheduling uncertainties."

On Saturday, Trump underwent a "routine, planned interim checkup as part of the regular, primary preventative care he receives throughout the year," Dr. Sean Conley said. Trump has "not had any chest pain, nor was he evaluated or treated for any urgent or acute issues," he continued. "Specifically, he did not undergo any specialized cardiac or neurologic evaluations."

When a president or other notable person visits Walter Reed, staffers are usually notified ahead of time, people familiar with the matter told CNN, and this didn't happen on Saturday. Several doctors who treated former presidents and vice presidents said they found the unannounced hospital visit worrisome, including Dr. Jonathan Reiner, a cardiologist who treated former Vice President Dick Cheney. "It's concerning that there hasn't been any transparency in what occurred on Saturday," he told CNN before the memo was released.

In the memo, Conley said next year, he will put together a report with a full summary of Trump's labs and exam. With the president's consent, Conley did share Trump's cholesterol numbers, which are down from earlier this year. Catherine Garcia

On the eve of Lt. Col. Alexander Vindman's public testimony before House impeachment investigators, Sen. Ron Johnson (R-Wis.) sent a letter to House Republicans, questioning Vindman's credibility.

Vindman, the National Security Council's top Ukraine expert and a Purple Heart recipient, is set to testify on Tuesday. He listened to President Trump's July 25 phone call with Ukrainian President Volodymyr Zelensky, and immediately shared his concerns over Trump's request that Zelensky launch an investigation into a political rival, former Vice President Joe Biden, and his son, Hunter.

In his letter, Johnson opines that there are "bureaucrats and staff members within the executive branch" who have "never accepted President Trump as legitimate and resent his unorthodox style and his intrusion onto their 'turf.' They react by leaking to the press and participating in the ongoing effort to sabotage his policies and, if possible, remove him from office. It is entirely possible that Vindman fits this profile."

Johnson tried to defend Trump throughout the letter, saying he could not recall Trump ever talking to him about the Bidens, while also attacking the whistleblower whose complaint about Trump's call launched the House impeachment inquiry. "If the whistleblower's intention was to improve and solidify the relationship between the U.S. and Ukraine, he or she failed miserably." Catherine Garcia

Since being deported from the United States, Maria Butina has received several job offers in Russia, including one with the human rights commission.

Butina, 31, pleaded guilty last year to one count of conspiring to act as a foreign agent for Russia. She infiltrated the National Rifle Association and influenced Republican and conservative activists to promote Russian interests in the 2016 presidential election. She was sentenced to 18 months in prison, but was released last month after serving 15 months. She was deported on Oct. 26.

When she arrived back in Russia, Butina was greeted by cheering supporters. She made her first public appearance since then on Monday, alongside the country's human rights commissioner, Tatyana Moskalkova. Moskalkova invited Butina to "work in our group defending compatriots abroad," explaining: "I'm sure together we'll be able to do a lot of good for people who've ended up in tough situations abroad." Butina did not say if she'll take the job or if she'll accept another offer to work in Russia's lower house of parliament, Reuters reports.

Also on Monday, Butina's former boyfriend, conservative political operative Paul Erickson, pleaded guilty to one count of wire fraud and one count of money laundering. Authorities say the South Dakota businessman promised dozens of clients returns of up to 150 percent, but in reality stole $2.3 million from them. He was accused of using this money on personal expenses for Butina. Catherine Garcia

Two prison guards assigned to watch accused sex trafficker Jeffrey Epstein on the night he took his own life are expected to be charged with falsifying prison records, a person with knowledge of the matter told The Daily Beast on Monday.

Epstein was arrested on July 6 and held in New York City's Metropolitan Correctional Center while awaiting trial on charges of sex trafficking and conspiracy. Epstein was in a special unit, and while he was no longer on suicide watch, guards were supposed to check on him every 30 minutes. On Aug. 10, he was found hanging from a bed sheet in his cell, and the New York City medical examiner confirmed that his death was a suicide.

Federal investigators have been trying to determine how Epstein was able to take his own life, and there have been multiple reports that the unnamed guards fell asleep on the job and altered records to cover their tracks. The charges against the guards could be filed as soon as Tuesday, The Daily Beast reports. Catherine Garcia

A career official at the Internal Revenue Service who filed a whistleblower complaint over the summer, accusing at least one political appointee at the Treasury Department of trying to interfere with an audit of President Trump's tax returns, met with Senate Finance Committee staff members earlier this month, a congressional aide told The New York Times.

The whistleblower spoke with staffers for Sen. Chuck Grassley (R-Iowa) and Sen. Ron Wyden (D-Ore.), the chairman and ranking Democrat of the Senate Finance Committee. The whistleblower contacted the staff of the House Ways and Means Committee in July, claiming that political appointees were getting involved in the audit and putting pressure of some kind on senior IRS officials, the Times reports.

Details of the allegations remain unclear, and the House Ways and Means Committee is still reviewing the complaint. "We generally do not comment on whistleblower meetings, their contents, or even if they happened," Michael Zona, a spokesman for Grassley, told the Times. "Additionally, federal law prohibits the discussion of protected taxpayer information."

A person familiar with the matter told the Times the complaint does not directly implicate Treasury Secretary Steven Mnuchin, who has refused to comply with a congressional request to release six years worth of Trump's personal and business tax returns. Catherine Garcia