Morning Must Reads: September 16

Get the popcorn and/or your shot glasses ready. It’s debate day.

Eleven candidates will take the stage at the primetime debate, which is set up to be a showdown between the field and Donald Trump. But first, five candidates will face off in the undercard debate, facing the ever-more-difficult task of justifying their presence. CNBC, which is hosting the next debate in October, has yet to set its qualifications or format, but many GOP insiders believe it will dispense with the two-tiered system in hopes of winnowing the field.

One thing has become clear in recent weeks—he’s becoming a candidate, referring to notes and staying on message in ways he seemed incapable or unwilling to do when he first entered the race. This new discipline is only enhancing his staying power in the race. And as Trump is facing more fire from the GOP’s conservative wing over his unorthodox policy proposals, Vice President Joe Biden unleashed on the Republican front-runner Tuesday night, calling his policy proposals “sick” and “xenophobic.”

Trump haikus. Bernie Sanders dodges the press. And John Kasich takes fire in New Hampshire.

Here are your must-reads:

Republican Candidates Prepare to Hit Trump at Second Debate
TIME’s Philip Elliott sets the scene from LA

Conservative Anti-Tax Group Targets Trump
The Club for Growth goes after the front-runner, TIME’s Alex Altman reports

Donald Trump, Firework of Campaign Trail, Shows a More Measured Side
The front-runner becomes a candidate [New York Times]

U.S. Training Helped Mold Top Islamic State Military Commander
Unintended consequences in a turbulent region [McClatchy]

Sound Off

“One guy absolutely denigrated an entire group of people, appealing to the baser side of human nature, working on this notion of xenophobia in a way that hasn’t occurred in a long time. Since the Know Nothing party at the end of the 19th century.” — Vice President Joe Biden on Donald Trump at a reception Tuesday night, calling Trump’s message “sick”

“Mr. Trump’s going to be hearing quite a lot from me.” — Carly Fiorina in an interview with CNBC in advance of the debate

Bits and Bites

Now You Can Donate to a Politician With a Tweet [TIME]

15 Haiku, by Donald Trump [Washington Post]

Democrats Move to Beef Up Fund-Raising With Staff Overhaul [New York Times]

Bernie Sanders Hasn’t Taken Questions at 10 Events [Boston Herald]

Kasich Super PAC Hits Walker [Cleveland.com]

Trump and Schwarzenegger: A Political Comparison [Los Angeles Times]

Progressive Groups Spar Over Clinton-Alternative Effort [MSNBC]

Analysts Detail Claims That Reports on ISIS Were Distorted [New York Times]

New Clinton Super PAC Ad Evokes Ronald Reagan [Politico]

Kelly Ayotte Takes a Swipe at John Kasich [Politico]