Danielle Kurtzleben

Updated at 12:15 p.m. ET

Vermont Sen. Bernie Sanders is canceling presidential campaign events "until further" notice following a heart procedure, campaign senior adviser Jeff Weaver said Wednesday morning.

Weaver said in a brief written statement that Sanders "experienced some chest discomfort" during a Tuesday evening campaign event.

Once again, health care took up a large chunk of a Democratic primary debate. Once again, there were fights over costs, coverage and whether the party is growing too extreme.

But this time, all of the front-runners were onstage together, providing the first opportunity for all of them to take direct aim at each other and their vastly differing health care plans. It made for some heated exchanges, putting "Medicare for All" supporters on defense. But it also showed clearly that some candidates are cautious not to criticize others' proposals too harshly.

The lineups are set for the first Democratic presidential primary debates.

Among the debate matchups: Former Vice President Joe Biden, currently leading in primary polls nationally, will face off against Vermont senator and 2016 candidate Bernie Sanders, as well as California Sen. Kamala Harris and South Bend, Ind., Mayor Pete Buttigieg.

Meanwhile, Massachusetts Sen. Elizabeth Warren will face New Jersey Sen. Cory Booker and Minnesota Sen. Amy Klobuchar.

Beto O'Rourke got lots of attention from his campaign kickoff in Keokuk, Iowa. And thanks to some of his comments, not all of that attention was good.

At the start of his speech, O'Rourke referenced a call from his wife, Amy, "who's back in El Paso, Texas, where she is raising, sometimes with my help, Ulysses, who's 12 years old, Molly, who's 10, and their little brother, Henry, who is 8 years old."

To some Democratic voters, that seemed like a flip acknowledgment that he was handing off parenting duties to his wife while he pursued his political dreams.

Americans could be forgiven for having poll whiplash this week.

"Shock poll: Americans want massive cuts to legal immigration," said a headline from the Washington Times.

Updated at 1:26 a.m. ET Wednesday

Republicans in Congress approved a sweeping and controversial $1.5 trillion tax overhaul, with the Senate voting early Wednesday along straight party lines to move the measure forward.

Nearly 9 in 10 Americans believe that "a zero-tolerance policy for sexual harassment is essential to bringing about change in our society."

At a time when partisan opinions are so polarized on a range of issues, Republicans and Democrats are relatively similar in believing that society should crack down hard on sexual harassment, a new poll from Ipsos and NPR suggests.

Updated at 4:58 p.m. ET

Republicans are sprinting to push their tax plan through Congress by the end of the year, and with that quick timeline comes a breakneck news cycle. The Senate tax overhaul plan underwent some big changes overnight, with GOP members in that house confident they could get the bill passed. But with a GOP senator now saying he opposes the bill and several others uncommitted, it could have a tougher time passing.

In the wake of the deadliest mass shooting in modern U.S. history, most Americans — regardless of party — favor tightening restrictions on firearms, according to a new NPR/Ipsos poll.

But significant partisan divides remain — and perhaps relatedly, they exist alongside divides in knowledge about guns in America.

Eight-in-10 Americans told the pollsters they favor bans on assault weapons, high-capacity ammunition magazines and "bump stocks," an accessory used by the Las Vegas shooter that allows a semi-automatic rifle to fire like an automatic weapon.

Updated at 11:40 p.m. ET

The Trump administration said Thursday that it would end the Affordable Care Act's cost-sharing reduction payments designed to help low-income Americans get health care. Not paying the subsidies, health care experts have warned, could send the health insurance exchanges into turmoil.

After learning that President Trump is working with Democratic congressional leaders on codifying the Deferred Action for Childhood Arrivals program, furious Trump supporters burned their Make America Great Again hats.

The Capitol Hill health care fight sure seemed dead. After Republican proposals to overhaul the Affordable Care Act, also known as Obamacare, failed to pass a Republican-controlled Congress, lawmakers looked poised to move on to other topics, like a tax overhaul. But this week, proposals from both the left and the right are grabbing headlines.

In announcing the president's decision to end the Deferred Action for Childhood Arrivals program, Attorney General Jeff Sessions stressed the legal arguments for that decision.

The recent violence in Charlottesville, Va., amplified an ongoing struggle in America about who experiences discrimination and to what extent. Many of the white nationalists who rallied in Charlottesville, for example, feel that white people are discriminated against as much as, or more than, minority groups.

Updated at 4:59 p.m. ET

President Trump stood by his heavily criticized defense of monuments commemorating the Confederacy in a series of tweets Thursday morning. Trump said removing the statues of Confederate generals meant removing "beauty" — that would "never able to be comparably replaced" — from American cities. As he did in a Tuesday press conference, he also attempted to equate some Confederate generals with some of the Founding Fathers.

Strung together, the tweets read:

Updated at 6:05 p.m. ET

In a press conference on Tuesday, the president of the United States appeared to equate white supremacist marchers with counterprotesters who recently clashed in Charlottesville, Va.

Way back at the start of his presidency, Donald Trump created a stir with his first calls to leaders of U.S. allies.

Updated 6:56 p.m. ET

Senate Republicans on Thursday released a revised version of the Better Care Reconciliation Act, their plan to replace the Affordable Care Act.

Updated at 2:32 p.m. ET

Senate Republicans unveiled their long-awaited health care overhaul proposal on Thursday. The Senate bill, called the "Better Care Reconciliation Act," would repeal major parts of the Affordable Care Act, also known as Obamacare. The broad outlines of it look a lot like the House bill, the American Health Care Act, which was passed in May.

The revised Republican bill to repeal and replace the Affordable Care Act will leave 23 million more people uninsured in 2026 than if that act, also known as Obamacare, were to remain in place. The GOP bill would also reduce the deficit by $119 billion over 10 years.

Friday night, President Trump took to Twitter to deliver one of his favorite insults to journalists: "The FAKE NEWS media (failing @nytimes, @NBCNews, @ABC, @CBS, @CNN) is not my enemy, it is the enemy

This week, Donald Trump told members of Congress that he would have won the popular vote, were it not for 3 to 5 million votes cast against him by "illegals." And when asked about it at the Tuesday press briefing, White House press secretary Sean Spicer affirmed that "the president does believe that."

But there is no evidence.

The annual turkey pardon is a silly tradition, and President Obama knows it. On Wednesday, before pardoning turkeys named Tater and Tot, Obama summed up his feelings about this particular duty.

"It is my great privilege — well, it's my privilege — actually, let's just say it's my job to grant them clemency this afternoon," Obama said.

Protests raged after Americans elected Donald Trump president. Another massive protest is planned for inauguration weekend. Online, his opponents express their dread that he could be "normalized."

Before the election, more Americans believed Trump's opponent had the better temperament and ability to serve as president.

And, yet, half of Americans now believe Trump will do a good job as president.

Every presidential election manages to feel new somehow. Even amid the wall-to-wall cable coverage and poll frenzies and day-before-the-election, man-on-the-street interviews with still-undecided voters and shock (shock!) when a candidate flip-flops, every four years, there's a sense that this time — this time — is different. (Remember that whole recount thing?)

And then there's 2016.

The results from Tuesday's four primary and caucus states are in: three wins for Trump, one each for Clinton and Cruz, and one surprising, narrow victory for Sanders.

Bernie Sanders' tight win over Hillary Clinton in Michigan is the biggest news out of Tuesday night's presidential nomination races. Though Clinton had led consistently in recent polls, Sanders won by less than 2 percentage points with 99 percent of precincts reporting.

Donald Trump picked up his first congressional endorsements this week, and today he scored another major backer: one of his former rivals, Chris Christie.

"I've gotten to know all the people on that stage. And there is no one who is better prepared to provide America with the strong leadership that it needs, both at home and around the world, than Donald Trump," the New Jersey governor said at a news conference in Fort Worth, Texas.

Ahead of Thursday's Republican debate, pundits agreed that someone — and Marco Rubio in particular — needed to attack Trump.

Hillary Clinton will win the Nevada Democratic caucuses, the Associated Press is reporting.

With 84 percent of the precincts reporting, Clinton has 52.5 percent of the vote, compared to Sen. Bernie Sanders' 47.5 percent.

"Tens of thousands of men and women with kids to raise, bills to pay, and dreams that won't die — this is your campaign," she told a crowd at Caesar's Palace in Las Vegas. "And it is a campaign to break down every barrier that holds you back."

Here are a few safe bets for Tuesday's State of the Union: There will be dozens of applause breaks, endless GIF-worthy moments and a laundry list of proposals (not to mention lots of reporters using the phrase "laundry list" for the first — and maybe only — time this year).

One more bet: Most of those proposals won't be successful.