"No matter what it is - don’t fall for it," Manley argued. "Your goal is to show everyone watching that you deserve to be in the stage for the long haul and not just some flash in the pan."
Taking the candidates in alphabetical order for Thursday night, a quick review shows that most of these Democrats are in need of some kind of a campaign boost:
+ Sen. Cory Booker (D-NJ) - Booker's own people say he will use this debate as a chance to 'introduce' himself to voters. Booker had some recent attention over a spat with front runner Joe Biden, but has not been a major presence.
+ Julian Castro - A former mayor of San Antonio, and member of the Obama Cabinet, Castro is often publicly confused with his brother, a member of Congress from Texas.
+ Bill de Blasio - A mayor of New York City should be a major factor in the broader race for President - just because of that position - but it has not turned out that way so far for de Blasio.
+ John Delaney - The former Congressman from Maryland has been in the race officially for the longest time of any current Democratic candidate, but has little to show for it at this point.
+ Tulsi Gabbard - The Congresswoman from Hawaii has been on the fringes of the race since announcing her bid for President. Like most of the others on stage tonight, Gabbard is struggling to get noticed nationally.
+ Jay Inslee - The former Congressman and current Governor of Washington State has been here in Miami for the last few days pushing his main issue, climate change. Inslee certainly has the policy chops to run for President, but it's not clear if he can make the jump into the top tier of candidates.
+ Amy Klobuchar - The Senator from Minnesota was on my flight down to Miami with a staffer, a low key arrival when you compare it to the events by O'Rourke and Warren at the same time in Miami. This might seem repetitive, but Klobuchar is also in need of a boost in this race.
+ Beto O'Rourke - The former Congressman from Texas may be the second best known of the Democrats on stage on this first night, but that hasn't guaranteed him a spot in the top tier of Democratic hopefuls. Still, he is a known name, and that gives him a leg up on a number of others tonight.
+ Tim Ryan - the Ohio Congressman is well known on Capitol Hill, but has made little impact so far in the broader race for President. From an industrial area of Ohio, Ryan has a unique message from the Rust Belt for Democrats. He's another one who can use tonight to introduce himself to a broader audience.
+ Elizabeth Warren - the luck of the draw put Warren with this group on Thursday, as she is by far the biggest candidate, with Joe Biden, Bernie Sanders, and others in the debate scheduled for Thursday. At a town hall in west Miami on Tuesday, the strength of Warren's operation was on display, as she drew about 1300 interested voters. Yes, those aren't President Trump numbers, but she clearly has a message that is resonating with Democratic Party voters.
Before tonight's debate Warren waded into the fight over illegal immigration, and how the federal government is dealing with an influx of children over the southern border, housing them in facilities all across the country.
"Locking people up for money is not what the United States of America should be about," Warren told reporters outside a detention facility for immigrant children south of Miami, in Homestead, Florida.
Protesters outside the facility chanted, "Shut it down!" as Warren arrived with a number of reporters and cameras in tow, after promising at a Tuesday night town hall that she would make an impromptu visit to the shelter.
Klobuchar was also making a visit to Homestead, as she joined Warren and six other Democratic Senators in sending a letter to federal officials demanding information on whether those companies in charge of such shelters are violating their contracts.
"Based on recent reports, there is significant evidence that some federal contractors and grantees have not provided adequate accommodations for children," the group wrote in a letter to the Department of Health and Human Services.
Thursday night's debate will feature Michael Bennet, Joe Biden, Pete Buttigieg, Kirsten Gillibrand, Kamala Harris, John Hickenlooper, Bernie Sanders, Eric Swalwell, Marianne Williamson, and Andrew Yang.
Several other Democrats in the race - including Montana Governor Steve Bullock - did not qualify for this first debate.
Bullock won a notable endorsement in Iowa on Tuesday, and is spending the two debate days on the road in Iowa and New Hampshire.