More than $400 million has already been contributed in the 2016 presidential campaign.

Here are answers to five questions about the money race.

Republican presidential candidate Scott Walker campaigned in the GOP stronghold of DuPage County, Ill., on Thursday, presenting himself as an experienced alternative to front-running Donald Trump and others surging because they express voter anger at Washington.

Speaking for 20 minutes at the county GOP's summer reception at a restaurant in Downers Grove, Walker also pledged to challenge the Republican establishment overseeing Congress.

"There is a real concern across America. There is a real frustration across America, not just amongst Americans but amongst Republicans. They're saying, 'Hey, wait. We've got a Republican House. We've got a Republican Senate. When are we going to get something done?' And for people who have that concern, I've got the answer," he said.

Read more of this report from the Chicago Tribune's Rick Pearson.

Questions about Bush's views on the Iraq war have come up on several occasions in the last few months as he runs for the Republican presidential nomination.

In May, before he formally declared, Bush was asked about the war, and he said he would have authorized the invasion -- as did his brother, the president at the time, George W. Bush.

After calibrating and recalibrating for several days, Bush finally concluded, “Knowing what we know now, I would not have engaged ... I would not have invaded Iraq.”

After Bush's comments, The Times' Mark Z. Barabak reflected upon how echoes of the Iraq war are playing into the 2016 presidential race.

Donald Trump and the other candidates for the 2016 Republican presidential nomination have not seen the last of Fox News Channel's Megyn Kelly.

Fox has another debate scheduled in January before the Iowa caucuses and Kelly, "Special Report" anchor Bret Baier and "Fox News Sunday" anchor Chris Wallace will be moderating again, a representative for the channel confirmed.

The trio's pointed questioning of Republican front-runner Donald Trump at the Aug. 6 debate in Cleveland prompted harsh criticism from the candidate and his supporters. Trump's attacks on Kelly on social media and in TV interviews became so heated, Fox News Chairman Roger Ailes called and told him to cool it.

Read more of this report from the Times' Stephen Battaglio.

When in California, why not raise some money?

That's the plan for Jeb Bush ahead of the Sept. 16 GOP debate at the Reagan Presidential Library near Simi Valley.

Bush's wife, Columba, and his son Jeb Jr. will attend a high-dollar luncheon in Los Angeles the day before the debate. Co-chairs of the event are being asked to raise $27,000 for the campaign, while those who just want to attend must contribute $1,000, according to an invitation to the event. The day after the debate, Bush will be a guest at a breakfast in Bakersfield where guests will be asked to raise and contribute similar amounts.

Bush, who has raised more money than any of the GOP hopefuls, received less than 7% of his contributions from California, according to a Times analysis of campaign contributions from last quarter. Much of Bush's campaign money has come from Florida and Texas, states where he has deep political roots.

A super PAC supporting his candidacy, overseen by Mike Murphy, a Los Angeles-based GOP operative who advised John McCain's 2008 presidential bid, raised $103 million.

While in Southern California for next month's debate, some candidates will also look to make inroads with local Republicans, who are outnumbered in this deeply blue state.

Wisconsin Gov. Scott Walker will be the headline speaker at the California Republican Party's fall convention in Anaheim on Sept. 18. Former Arkansas Gov. Mike Huckabee will also attend.

Your morning Trail Guide feels strongly that the Minnesota State Fair is the nation's best state fair as measured by most commonly accepted criteria -- things on a stick, butter art, potentially lethal rides, enormous animals. It gets bonus points in the "baked goods available by the bucket" category.

There is one exception, of course. Iowa wins by a mile on political pandering. By tradition (and is it state law?), the candidates must show their faces at the fair, ready to do and eat almost anything to please Iowans. This is not an event for the proud, the vain or the dieting.

Yes, Donald Trump does plan to attend on Saturday.

But the fun officially starts today. We'll be posting the highlights along the way. For now, enjoy this classic. Former New Mexico Gov. Bill Richardson, a 2008 cycle contender, posing with cow made out of butter after apparently giving his all in the hot, Iowa sun.

For more like this, the Des Moines Register has the complete photo collection of good, bad and awkward fair moments.

Jeb Bush is one of the Republicans promising to campaign "everywhere," meaning outside of traditional GOP strongholds and in African American, Latino and urban communities. Last night he put that promise into practice, with rocky results.

Bush visited North Las Vegas, a working-class suburb hit hard by the housing bust and a good distance from the tony Las Vegas-areas communities that tend to draw his rivals. It's nearly 40% Latino and 20% black. Almost a quarter of the city's population is foreign born.

The Times' Seema Mehta has this report from what became a raucous event. Black Lives Matter demonstrators were escorted from the building, Mehta reports, and when Bush was asked about his immigration plan, his answer was booed.