Michigan Rep. Justin Amash is really taking this whole Independence Day thing to heart. The congressman announced in a Washington Post op-ed Thursday that he is leaving the GOP to become an independent.

"Today, I am declaring my independence and leaving the Republican Party," Amash, a libertarian, wrote in a column that denounces the two-party system as an "existential threat to American principles and institutions." He said party loyalty has eclipsed Congress' true purpose of serving the American people, and called upon readers to "join me in rejecting the partisan loyalties and rhetoric that divide and dehumanize us."

Amash's departure from the GOP was "nearly a decade in the making," says HuffPost's Matt Fuller. Indeed, Amash has been at odds with the party for some time. He remains the only congressional Republican to call for President Trump's impeachment following the release of Special Counsel Robert Mueller's report detailing Trump's possible obstruction of justice. He has frequently joined Democrats in various votes against Trump's initiatives, like the border wall. In June, he resigned from the House Freedom Caucus that he co-founded in 2015 and faces a formal censure from that body.

Recently, CNN dubbed Amash "the loneliest member of Congress," and Amash himself told Vox that "a lot of the people who once stood with me are no longer there."

So, what does his departure mean? As Reason notes, Amash was facing a tough upcoming primary challenge for Michigan's third congressional district. His new affiliation means he can try to run for re-election as an independent. But there's also lingering speculation that he could launch a 2020 challenge against Trump. Unless or until he rules this out, Reason writes, the coming months "will be a festival of guessing, gamesmanship, and gossip." Oh, goodie. Jessica Hullinger

With her two wins on Sunday, Simone Biles became the most decorated gymnast in world championship history.

Biles took home two gold medals — one for the balance beam and the other for her floor exercise — and now has 25 World Championship medals. Earlier in the competition, she won gold in the team competition, all-around and vault; she came in fifth-place on the uneven bars. The 22-year-old's Sunday wins put her ahead of Vitaly Scherbo, who earned the previous record of 23 world medals during the 1990s.

Biles' floor performance was so outstanding, with a triple-twisting double back, she earned a score of 15.133, one point higher than the second-place finisher, U.S. gymnast Sunisa Lee. Catherine Garcia

President Trump made a grave mistake by pulling back troops in Syria last week, allowing Turkey to launch a military offensive against the Kurds, a retired four-star Marine general told CNN on Sunday.

"There is blood on Trump's hands for abandoning our Kurdish allies," Gen. John Allen said. The Kurdish-led Syrian Democratic Forces worked with the United States for several years to fight the Islamic State, and held control of the northeastern border area. Since the Turkish assault began last week, video footage has emerged purportedly showing Turkish-backed militia fighters shooting Kurdish prisoners. This, Allen said, is a "full-blown ethnic cleansing."

The Kurds oversee prisons holding thousands of ISIS fighters, their families, and supporters, and hundreds escaped during fighting over the weekend. Allen — the former commander of American forces in Afghanistan and former special presidential envoy for the Global Coalition to Counter ISIS during the Obama administration — said this chaos was "completely foreseeable" and "what happens when Trump follows his instincts and because of his alignment with autocrats."

Allen is also unmoved by Trump's approval of $50 million in aid to Syria. This gesture rings "hollow," he said, and there's no way to say if the money will go where it should. "Who's going to administer it and for whom?" Allen said. "Hundreds of thousands are fleeing and the relief agencies are on the move." Catherine Garcia

President Trump's decision to move U.S. troops from northern Syria, paving the way for Turkey to launch an assault against the Kurds, prompted the Kurds on Sunday to reach a protection deal with the Syrian government.

Under this agreement, Syrian government troops will be able to enter Kurdish-controlled northeastern Syria for the first time in years, The New York Times reports. The United States and the Syrian Democratic Forces, a Kurdish-led militia, spent the last several years as allies, fighting against the Islamic State.

There are still ISIS sleeper cells in Syria, and many fear that the Turkish invasion could lead to the terror group's resurgence. Thousands of suspected ISIS supporters are being held in prisons guarded by Kurds, and hundreds escaped during fighting on Saturday and Sunday. Two U.S. officials told the Times the military recently tried to transfer five dozen "high value" ISIS detainees, but feeling betrayed, the Kurds said no.

The Syrian government, which counts Iran and Russia as its allies, said on Sunday it will fight the "Turkish aggression," while Turkish President Recep Tayyip Erdogan said his troops have control over about 70 square miles of territory in northern Syria. U.S. Defense Secretary Mark Esper on Sunday morning announced all American troops will withdraw from northern Syria, in order to stay out of the crossfire. Catherine Garcia

It looks like Sen. Bernie Sanders (I-Vt.) is beginning to distance himself from his good friend Sen. Elizabeth Warren (D-Mass.) policy-wise.

The two Democratic presidential candidates have always gotten along well and are generally ideological allies, especially relative to many of their primary competitors. But Sanders was pretty clear in an interview that aired on ABC's This Week Sunday that Warren has a ways to go before she's at the same point on the political spectrum.

Sanders praised Warren's tenure as a senator and reaffirmed their friendship, but he said "there are differences" in their platforms, namely the fact that Warren has maintained she is a capitalist "through her bones." He said the country doesn't need more regulation, but rather a "political revolution" and he believes he's the only candidate who will stand up to the corporate elite in the U.S. and say "enough." He said that Warren would speak for herself on the matter, but, for the moment, Sanders, who considers himself a democratic socialist, thinks her adherence to capitalism is reason enough to separate them.

The initial analysis of Sanders' comments seems to be that Sanders recognizes he's falling behind Warren in the race, and understands focusing on where they differ might be his best chance at getting back in contention. Tim O'Donnell

Sen. Ted Cruz (R-Texas) had some mixed reviews for the Trump administration Sunday.

During an appearance on CBS' Face the Nation, Cruz told host Margaret Brennan that he believes it was inappropriate for President Trump to have asked the Chinese government to investigate former Vice President Joe Biden and his son, Hunter. Cruz said "elections in the United States should be decided by Americans and it's not the business of foreign countries to be interfering in our elections."

He did, however, praise the administration for agreeing to release the transcript of Trump's phone call with Ukrainian President Volodymyr Zelensky, in which Trump is accused of pressuring his Ukrainian counterpart to investigate the Bidens. And the senator wasn't ready to let the Bidens off the hook, either, saying that if there's "credible evidence" of wrongdoing, he would support a Justice Department probe. He also had some advice for Biden — Cruz urged him to follow in Trump's footsteps and release the transcript of his own conversations with Ukraine from when he was vice president, so that the American people can judge for themselves. Tim O'Donnell

One game is already under way in the NFL, but there's a lot more to come. Here are four Week 6 games to keep an eye on:

Kansas City Chiefs vs. Houston Texans, 1 p.m. ET on CBS — This matchup between two potential playoff teams could be an offensive explosion. Kansas City and Houston feature two of the game's top young playmakers in quarterbacks Patrick Mahomes and DeShaun Watson, respectively. Houston was clicking on all cylinders last week when they torched the Atlanta Falcons for 53 points behind a stellar Watson performance. Kansas City and Mahomes, meanwhiel, played their worst game of the season against the Indianapolis Colts last week.

Miami Dolphins vs. Washington Redskins, 1 p.m. ET on Fox — Full disclosure: this is a bit tongue-in-cheek. Miami and Washington are probably two of the worst teams in the league this year, but one of them will have to win this one. It's also Washington's first game since firing head coach Jay Gruden earlier this week. In the long run, though, this is about the race for the number one pick.

Minnesota Vikings vs. Philadelphia Eagles, 1 p.m. ET on Fox — Alright, back to quality football. After a rough start to the season, the Eagles look formidable again, but a road game in Minnesota remains a tall task. Minnesota has had an up and down season, but they're coming off a strong performance against a weak New York Giants team. This should be a good litmus test for two 3-2 teams aiming for division crowns.

Los Angeles Rams vs. San Francisco 49ers, 4:05 p.m. ET on Fox — This promises to be an exciting divisional game. The Rams have been a bit of disappointment this year, but knocking off the 49ers, who remain the only undefeated team not called the New England Patriots, would be a great way to shake off some of their post-Super Bowl rustiness. The Niners, meanwhile, just destroyed the Cleveland Browns last Monday and look like a legitimate Super Bowl contender. Tim O'Donnell