Democrats in Arizona, Idaho and Utah went to the polls Tuesday, March 22, to select a presidential candidate. This post was updated throughout the day with exit-poll information, analysis and results. For Republican contest analysis and results, follow this link.

Update (March 23, 6 a.m. PT): Final results

"Western Tuesday" winners

Arizona: Hillary Clinton (58%)

Utah: Bernie Sanders (80%)

Idaho: Bernie Sanders (78%)

Update (March 22, 8:40 p.m. PT): The battle continues

With her victory in Arizona, former Secretary of State Hillary Clinton maintains momentum for her campaign, regardless of how the final results turn out tonight in Utah and Idaho. Next up for the Democrats: caucuses on Saturday in Alaska, Hawaii and Washington state. Then comes the Wisconsin primary on April 5. Clinton holds a negligible lead in the polls in the Badger State. If Sanders is going to have any chance of catching Clinton in the delegate hunt -- and that appears increasingly unlikely -- he must win in Wisconsin.

Update (March 22, 8:27 p.m. PT): Clinton wins Arizona

Hillary Clinton wins the Arizona Democratic primary, multiple news sources project. Arizona is the biggest prize of the night, but Bernie Sanders still could score victories in Utah and Idaho.

Update (March 22, 8:12 p.m. PT): Early results in Arizona

Hillary Clinton leads Bernie Sanders 61 percent to 36 percent with just under half of the ballots counted in Arizona.

Update (March 22, 6:50 p.m. PT): Results on the way

Arizona polls close in 10 minutes; the Idaho Democratic caucuses have ended and results will be available soon. Caucuses are continuing in Utah.

Update (March 22, 4:20 p.m. PT): What Bill Clinton meant

Hillary Clinton's campaign said Tuesday that former President Bill Clinton was talking about the do-nothing Republican Congress, not President Barack Obama, when he said Monday at a campaign rally that it was time to "put the awful legacy of the last eight years behind us and the seven years before that."

Clinton campaign press spokesman Brian Fallon said on social media that Vermont Sen. Bernie Sanders "is the only Dem in race who actually attacks" President Obama.

Update (March 22, 3:15 p.m. PT): Elizabeth Warren takes on Donald Trump

Elizabeth Warren was the great progressive hope last year. But the senator from Massachusetts declined to run for president, leading to the rise of Bernie Sanders.

Warren is still in the thick of things, however. She's been floated as a possible vice-presidential candidate on a ticket with Democratic front-runner Hillary Clinton. She hasn't said if she's interested in the number-two slot, but in recent days she has exhibited a key Veep attribute: a willingness to attack the other side and the ability to do it well.

"Let's be honest -- Donald Trump is a loser," Warren wrote on social media this week. "Count all his failed businesses. See how he kept his father's empire afloat by cheating people with scams like Trump University and by using strategic corporate bankruptcy (excuse me, bankruptcies) to skip out on debt." She continued:

"Trump seems to know he's a loser. His embarrassing insecurities are on parade: petty bullying, attacks on women, cheap racism, and flagrant narcissism. But just because Trump is a loser everywhere else doesn't mean he'll lose this election. People have been underestimating his campaign for nearly a year - and it's time to wake up."

Let's be honest - Donald Trump is a loser. Count all his failed businesses. See how he kept his father's empire afloat... Posted by Elizabeth Warren on Monday, March 21, 2016

Update (March 22, 2:20 p.m. PT): Clinton on terrorism response

Former Secretary of State Hillary Clinton has weighed in on the terrorist attacks in Belgium today by calling for a greater effort to defeat the Islamic State (ISIS) in their home bases in the failed states of Iraq and Syria.

"First of all, I think we do have to have a clear objective of defeating ISIS, of defeating the tactics and activities of terrorists," she told NBC News' Savannah Guthrie. "That's something I've been talking about for some time. I think the way to do that is to deprive them of territory in Syria and Iraq to stop the flow of foreign fighters, arms, weapons, and to take them on on the Internet, which they use in a quite sophisticated way. That means we've got to work with other countries. We have to work with our European friends and allies. We have to work with Middle Eastern and Muslim nations. And that means also that we've got to be smart about protecting us here at home."

Unlike Republican presidential candidates Donald Trump and Ted Cruz, Clinton is not calling for stopping Muslims from entering the U.S. or for patrolling Muslim neighborhoods. "I think there are a lot of things we have to do to intensify our efforts," she said. "I think closing our borders is not one of them. I think that even if we were to build a tall wall around the entire continental United States, the internet would still get over it. And so our challenge is to have a united effort to defend our country, to protect against terrorist attacks, to encourage everybody who sees or hears something suspicious to report it to law enforcement and to intensify our cooperation with other nations who have bits and pieces of information that can be helpful to us."

Her response to the comments from Trump and Cruz: "I don't think we want to be inciting more fears. I don't think we want to be playing to people's concerns so that we turn against one another."

Arizona, Utah, Idaho election preview (March 22, 10 a.m. PT)

Early this month, former Secretary of State Hillary Clinton admitted something we all already knew. She said she wasn't a "natural politician" like her husband Bill or President Barack Obama. By which she meant she wasn't very good at campaigning, at presenting herself for public consumption, at crafting an image.

This simple fact became obvious way back in 1992 when Americans were first being introduced to her. "I suppose I could have stayed home and baked cookies and had teas," she said, referring to the fact that she had pursued her legal career while Bill was governor of Arkansas rather than settling into the traditional first lady role. This was the tetchy defensiveness of a put-upon 1970s feminist, not the rousing "We've come a long way" triumphalism that she was going for. A few years later she again showed she had a tin ear for public perceptions when she complained about the "vast right-wing conspiracy" that was attacking her and Bill. She was roundly mocked by the conservative media, though it's difficult to deny she had a point.

In this reality-TV and Instagram age, Hillary Clinton is finding that her pragmatic, thoughtful, well-briefed approach to politics might bring bureaucratic and legislative successes but it just doesn't play on the stump. MSNBC talker Joe Scarborough and others scolded her last week for her tendency to yell her speeches and the fact that she doesn't smile naturally when the spotlight is on her. She remains the front-runner for the Democratic presidential nomination, but Vermont Sen. Bernie Sanders, though for months widely viewed as nothing more than a protest candidate, has proved to be a surprisingly strong and relentless opponent.

Clinton had a big night last Tuesday, dramatically extending her delegate lead with a series of victories, but Sanders made clear he's marching on. Three more states vote Tuesday: Clinton has a big lead in the polls in Arizona, but Sanders could win Idaho and Utah.

Clinton has done well so far at the polls, particularly in the South, but of course Sanders has pulled off some impressive upsets along the way, such as in Michigan. And he insists the primary calendar is now moving into states more suited to his calls for free college education, expanded Social Security, single-payer health care and a "political revolution" to address income inequality.

"She creamed us in Mississippi and Louisiana and South Carolina," Sanders said last week. He added: "As we head to the West Coast, which is probably the most progressive part of America, I think as you go forward you're going to see us doing better and better."

Is he right? That's hard to say. The biggest remaining prize is June's California primary, and polls show Clinton up by an average of 13 percentage points in the Golden State. (On Saturday, Democrats in Alaska, Hawaii and Washington vote in caucuses.)

Also working against the long-shot Sanders campaign is that Clinton, trying to be a "natural politician," has shifted to the left in response to the Vermont senator's challenge. Sanders sees that as a victory for him: "Hillary Clinton has moved over the last 10 months to the positions I've been advocating for the last 20 or 30 years," he said recently. "Our history in politics is very different and I think the people of this country deserve to know that."

Voters might not take his point, seeing only that Clinton and Sanders have similar messages while Clinton also has the powerful cloak of invincibility that every high-profile front-runner wears. But though the delegate math is against the Sanders campaign, Sanders senior adviser Tad Devine says anything can still happen -- starting Tuesday. "We're closing very hard," he told MSNBC over the weekend. "Bernie closes very well."

-- Douglas Perry