Everybody had something to prove in Wednesday's Republican presidential debates. Donald Trump, who leads the pack, had to withstand the verbal parrying of the other nine men and the sole woman sharing the main stage with him without looking like a bully.

That woman, Carly Fiorina — elevated from the second-string debate on Aug. 6 — needed to look like she belongs in the top tier. Ben Carson, who is rising in the polls, needed a substantive introduction to voters who might be focusing on him for the first time.

Jeb Bush and Scott Walker, once considered the race's powerhouses, were on a mission to rebound from their slide in the polls from double digits to single digits.

The others needed to get noticed before their support and money dry up. In Wednesday's early debate, all four candidates were making the case for their relevance.

The perils of being inconspicuous in a crowded field were evident last week when Rick Perry ended his campaign and Jim Gilmore failed to qualify for Wednesday's debate because of his low poll ratings. There are more debates to come, but this one could prove to be a turning point. And these might be the pivotal issues:

Donald Trump, businessman
Obama: Somehow [President Obama] just doesn't have courage.
On himself: I've been a politician for about three months. I'm obviously very good, as I'm No. 1 by a lot in every poll.
On Bush's attacks: More energy tonight. I like that.
Russia: [Vladimir Putin] has absolutely no respect for President Obama.Iran: The agreement was terrible, it was incompetent. … Nobody ever mentions North Korea.
Fiorina's looks: I think she's got a beautiful face. Jeb Bush, ex-Florida governor
On Trump: The next president … is going to have to fix an extraordinarily difficult situation. … That requires a steadiness, that requires an understanding of how the world works.
Special-interest money: People are supporting me because I have a proven record of conservative leadership.
Iran: It's not a strategy to tear up an agreement. … [We should] send a signal to Iran that we have Israel's back.
His brother's record: He kept us safe. Scott Walker, Wisconsin governor On Trump's experience: Mr. Trump, we don't need an "Apprentice" in the White House. We have one right now.
Special interests: I'd love to play cards with this guy, because Barack Obama folds on everything. You want someone who can actually take on the special interests … I'll do that as your president.
Economy: The real issue is about jobs. … You start on day one with repealing Obamacare.
Credentials: America needs a leader who will go big and bold again. Ben Carson, retired surgeon
Outsiders: Typically, politicians do things that are politically expedient. … That is not the reason that I have gotten into this thing. I am extraordinarily concerned about the direction of this country.
Minimum wage: We need to get both sides of this issue to sit down and talk about it.
Special interests: I have said to the people if they want me to do this, please get involved. We … have over 500,000 donations.
Immigration: If we don't seal the border, the rest … really doesn't matter.

Ted Cruz, Texas senator
Iran: Weakness is provocative and this Iranian nuclear deal is nothing short of catastrophic. … This deal will only accelerate Iran's acquiring of nuclear weapons.
Syria: If you vote for Hillary, you are voting for the Ayatollah Khamenei to have … a nuclear weapon.
Planned Parenthood: These [videos] are horrifying. … It is a felony … to sell the body parts of unborn children.
Immigration: What are the records of the various candidates? [Most] have embraced amnesty. Marco Rubio, Florida senator
Russia: I have an understanding of exactly what Putin and Russia are doing. … He is exploiting a vacuum that this administration has left in the Middle East.
Immigration: We have a legal immigration system that no longer works. … Here's the way forward: First, we must, we must secure our border.
Gun laws: Criminals by definition ignore the law.
Foreign policy: These are extraordinarily dangerous times. … You better be able to lead our country on the first day. Mike Huckabee, ex-Arkansas governor
Iran: This is really about the survival of Western civilization. ... We must simply make it very clear that the next president … will absolutely not honor that agreement.
Ky. clerk: Because the courts just decided that something was going to be … we have what Jefferson said was judicial tyranny. … You cannot make an accommodation for a democratically elected clerk from Kentucky?
GOP field: I'm delighted to be here with all of these guys, and would put any of them in an administration. Rand Paul, Kentucky senator
On Trump: Do we want someone with that kind of … careless language? … Would we not all be worried to have someone like that in charge of the nuclear arsenal?
Troops in Iraq: The first war was a mistake.
Foreign policy: Every time we've toppled a secular dictator we've gotten chaos and the rise of radical Islam.
Syria: Sometimes both sides of a civil war are evil.
Legal marijuana: I think the war on drugs has had a racial outcome. John Kasich, Ohio governor
Debate's focus: People at home want to know … what we're going to do to fix this place. … It's important we get to the issues.
Iran: Just doing it on our own I don't think is the right policy.
Planned Parenthood: We should defund Planned Parenthood. … There are ways to do it without shutting the federal government down.
Economy: At the end of the day, America's got to work.
Clinton: I want to spend my time talking about what I've done. Chris Christie, New Jersey governor
Outsiders: I wake up every morning as an outsider. … I vetoed 400 bills from a crazy liberal Democratic Legislature.
Planned Parenthood: Hillary Clinton … believes in the systematic murder of babies in the womb to preserve their body parts.
Climate change: We don't need … massive government intervention.Immigration: What we need to do is secure our border and we need to do it with more than a wall.
Trump vs. Fiorina: Stop this childish back and forth. Carly Fiorina, business executive
On Trump: Women all over the country heard very clearly what Mr. Trump said [when he said of her, "Look at that face"].
Outsiders: It's not that politicians are bad people, it's that they have been in that system forever.
Clinton: If you want to stump a Democrat, ask them to name an accomplishment of [hers].
Russia: Putin is someone we should not talk to.
Immigration: We have been talking about it for 25 years. This is why people are tired of politicians. Rick Santorum, ex-Pennsylvania senator (early debate)
Criticizing Trump: Personal attacks … please one person: Hillary Clinton.
Immigration: Wages are flat-lined. ... American workers are getting hurt by immigration and that's why they're upset.
ISIL: Once ISIL established a caliphate, the game changed. … They have legitimacy. We must take their ground.
Ky. clerk: People have a fundamental right [to] freedom of conscience.
Taxes: I'm going to propose a 20 percent … flat tax. Bobby Jindal, Louisiana governor (early debate)
On Trump: Let's stop treating Donald Trump like a Republican. … He doesn't care about policy. … He's not serious.
Immigration: We need to secure the border, period. … As president I'll get it done in six months. … Immigration without assimilation is invasion.
Syrian refugees: Let us draw a … direct line between this refugee crisis and this president's failed foreign policy. … Allowing more people into this country doesn't solve this problem. George Pataki, ex-New York governor (early debate)
On Trump: Trump is unfit to be president of the United States or the Republican nominee.
Immigration: You have to secure the border … but we can't ignore 11 million people who are here. … Give them legal status, make them part of an economy that will grow.
Taxes: I would throw out the entire corrupt tax code.
Ky. clerk: If she worked for me she would have been fired.
Iran: We are going to reject this deal on day one. Lindsey Graham, South Carolina senator (early debate)
Foreign policy: I'm running for president to destroy radical Islam.
Change: What I hope Republican voters, liberals, vegetarians, Democrats, you name it, will look for is somebody to lead us in a new direction.
Immigration: We're not going to deport 11 million people … but we'll start with felons and off you go. … If you don't control who gets a job, it never ends.
Ky. clerk: I want to make sure … you can practice your faith without governmental interference.