NOTABLES

--TODAY ON THE TRAIL: Republican frontrunner Donald Trump is off the trail today after his tax plan announcement yesterday, but fellow contender Jeb Bush will deliver an energy policy speech in Pittsburgh this afternoon, ABC's RYAN STRUYK notes. Ben Carson will be taking his campaign to church in North Carolina this afternoon, hot off strong fundraising numbers last night in the same state. Carly Fiorina, meanwhile, heads to Oklahoma City for a town hall meeting.

--WHAT DONALD TRUMP WANTS TO DO ABOUT TAXES. Republican presidential candidate Donald Trump introduced his detailed tax plan yesterday, ABC's JOHN SANTUCCI and BEN GITTLESON report. Trump's plan eliminates any federal income tax on individuals who earn less than $25,000 a year or on a married couple earning less than $50,000 per year, a potential tax break for 31 million households, according to the plan. "It will provide major tax relief for middle-income, and for most other Americans, there will be a major tax reduction," Trump said. "It will simplify the tax code." http://abcn.ws/1Fwubak

--ANALYSIS -- ABC's RICK KLEIN: No one has played the outside-inside game quite like Sen. Ted Cruz, whether that's rallying House members from his perch in the Senate, or working with outside groups who are seeking to oust his Senate colleagues in primary fights. That story got a new chapter Monday night, when Cruz railed against Senate leadership for an hour on the Senate floor -- then got slapped down by virtually all of his party's colleagues when he asked for a recorded vote, something a senator would normally get as a courtesy. He wasn't even given more time to speak in his push to defund Planned Parenthood, prompting Cruz to leave the floor in frustration and complain about an "unprecedented procedural trick." But his colleagues' point would be that what Cruz is doing marks the break with precedent. Now, deep into the presidential campaign, the suspicion is that Cruz is trying to use the Senate and its procedures to separate himself from the loathed institution he occupies a seat in. The message back from his colleagues is that they're not going to help. Anyone can take a shot at the establishment. But the establishment is more than capable of fighting back.

IN THE NOTE'S INBOX

UNIVERSITY OF CHICAGO INSTITUTE OF POLITICS LAUNCHES 'THE AXE FILES' PODCAST. David Axelrod, former top adviser to President Obama and the founder and director of the University of Chicago Institute of Politics, has launched a new podcast, "The Axe Files," a series of revealing interviews with key figures in the political world. The first episode is live and features Axelrod interviewing Democratic presidential candidate Bernie Sanders. Here's an excerpt: "I have a lot of respect for Bill Clinton, I think he did a lot of very good things. But I made ... on some very very important he was dead wrong. On deregulation of Wall Street, he worked with right wing, really right wing Republicans like Alan Greenspan." How to subscribe to "The Axe Files": https://iTunes.com/AxeFiles

ELSEWHERE ON THE TRAIL with ABC's RYAN STRUYK: Chris Christie and Bobby Jindal, struggling in the polls, aim to gain some momentum in the first-in-the-nation caucus state of Iowa today. John Kasich is in Chicago for a meet and greet. Lindsey Graham, who shined in the CNN undercard debate, will be on "The View" today. Kelley Paul, Rand Paul's wife, will be in South Carolina to pay the $40,000 filing fee to the state party just one day before the deadline to get on the ballot. Only George Pataki and Jim Gilmore have yet to pay it. Hillary Clinton has no events scheduled, but we expect the release of her full Lena Dunham interview today. Clips of it have been released over the last several days. Former President Bill Clinton and their daughter Chelsea Clinton, meanwhile, are in New York for the Clinton Global Initiative annual meeting. Also, the second part of their interview with E! News is set to air at 7 p.m.

THE BUZZ

with ABC's PAOLA CHAVEZ and VERONICA STRACQUALURSI

HOW CARLY FIORINA DEALS WITH BEING THE 'OTHER WOMAN'. Carly Fiorina wasn't the first GOP candidate to visit the Carolina Pregnancy Center during a campaign swing through South Carolina last week. But she was the first one invited to watch a woman receive an ultrasound 17 weeks into her pregnancy. "Wow, that shot of the spine is amazing -- how well-developed it is," Fiorina remarked, looking up at the ultrasound screen as she stood beside expectant mother Lacey Thomas, who lay outstretched on a hospital bed with her stomach exposed as the wooshing sound of her baby's heartbeat filled the room. As the only woman GOP presidential candidate in the race -- and now a serious contender for the nomination with rising poll numbers following strong performances in the two Republican debates -- Fiorina occupies a unique space with the 2016 contest. "[Whether] or not you're ready to ... support me, in your heart of hearts every single one of you know you would love to see me debate Hillary Clinton," Fiorina has told audiences from the stump. And while Fiorina is quick to tell voters she is not asking for their support on the basis of her gender but her qualifications, her gender identity serves as a contrast with the only other woman in the race. http://abcn.ws/1Ge8Ixz

NOTED: WHY FIORINA WANTS EVERYONE TO THROW OUT THEIR FLIP PHONES. Carly Fiorina is putting flip phone users on notice: You're going to have to upgrade under a President Fiorina. "How many of you have a flip phone?" Fiorina recently asked a town hall in South Carolina. A few people in the audience raised their hands as laughter filled the room. "It's okay, but you're going to have to upgrade soon," she continued. "You have 18 months to do so." It's all part of a vision the Republican presidential candidate has to give citizens a direct line of communication -- literally -- to the president. But the technology, Fiorina says, will only be compatible with smartphones. ABC's JORDYN PHELPS has more. http://abcn.ws/1NX6s41

BILL CLINTON SPRINGS INTO A BUSY POLITICAL FALL CAMPAIGNING FOR HILLARY. Former President Bill Clinton has been largely absent from the campaign trail since he first stood side by side with his wife, Hillary, during her campaign reboot on Roosevelt Island. Eight years ago, the former president was gearing up for his wife's first White House run, but he has had a relatively quiet summer this year, his campaign citing the president's focus on his foundation's Clinton Global Initiative annual meeting, which is currently taking place in New York City to coincide with the United Nations General Assembly. The annual meeting is President Clinton's springboard into a busy political fall, according to a staffer. This week will be jam packed for Mr. Clinton. ABC's MATTHEW CLAIBORNE has more. http://abcn.ws/1OCXPgJ

HOUSE BENGHAZI PROBE LONGER THAN WATERGATE. The House committee investigating the Benghazi attacks is now longer than the congressional investigation into the Watergate scandal, committee Democrats said earlier this week. ABC's BENJAMIN SIEGEL notes. http://abcn.ws/1hhvGgC

Editor's Note: An earlier version of the story published Sept. 28 incorrectly stated that the Benghazi Committee's investigation was the longest in congressional history.

WHO'S TWEETING?

@scottwongDC: Team @SteveScalise hand-delivered 246 letters to GOP lawmakers overnight asking for their support in the Majority Leader race

@MarkLeibovich: I heard about this guy, and wrote about him // Donald Trump Is Not Going Anywhere http://nyti.ms/1VnZgyF

@PhilipRucker: .@bterris on the steely & always-on Carly Fiorina ("as if she had a teleprompter in her brain") trying to show heart https://www.washingtonpost.com/lifestyle/style/carly-fiorina-killed-in-the-debates-but-how-would-she-do-in-person/2015/09/28/08555f7c-65ed-11e5-8325-a42b5a459b1e_story.html ...

@thehill: The Pros and cons of a Biden run: http://hill.cm/DVPErhM

@amyewalter: Happy Birthday to @gwenifill one of the smartest, hardest working and just plain awesome people in the biz!