By MICHAEL FALCONE ( @michaelpfalcone )

NOTABLES

• JUST WHEN YOU THOUGHT THE CAMPAIGN BATTLEFIELD WAS SET for the final weeks of the midterm election season, is there suddenly a new seat in play? Yes, Democrats believe, and it's in South Dakota. A top Democratic official tells ABC's JEFF ZELENY the party will spend at least $1 million in TV ads and a field operation in South Dakota. There is a fascinating three-way race unfolding in the state to fill the seat of retiring Sen. Tim Johnson. It's suddenly coming onto the radar because a third-party candidate is threatening to upend the race. The Democratic Senatorial Campaign Committee will start its advertising campaign as soon as Monday, an official said, in hopes of boosting Rick Weiland, a former aide to Sen. Tom Daschle. The Republican candidate, former governor Mike Rounds, is embroiled in a local controversy over state financing. The independent candidate is former Republican Sen. Larry Pressler. There is a fourth candidate in the race, too.

• THE LANDSCAPE, ACCORDING TO ZELENY: Democrats, of course, are struggling in several key races - Arkansas, Iowa, Louisiana - so they are also trying to expand their opportunities on Election Night. They believe South Dakota, like Kansas, could help the Democratic Party save the Senate. Republicans privately concede they are increasingly worried about the South Dakota race, but do not believe Rounds is in immediate danger of losing.

THE ROUNDTABLE

ABC's RICK KLEIN: It's remarkable that, less than four weeks before Election Day, the Senate playing field remains as unsettled as the electorate itself. The list of competitive races is expanding in unexpected and volatile ways. You may have been waiting for an Oregon or a Virginia to come on to the board, but who saw Kansas coming, much less South Dakota? This is what's frustrating prediction models, more than polling volatility inside individual races (which, truth be told, has been minimal). There are too many potential breakers to set up the long-expected wave. At the very least, Democrats have managed to inject enough uncertainty into enough unexpected places to create too many scenarios for firm predictions.

ABC'S JEFF ZELENY: A midterm election campaign that Republicans opened a year ago with relentless criticism of Obamacare is closing on a far different theme: A dark and foreboding warning about safety and security. Television ads are popping up across the country, questioning whether Democratic candidates can sufficiently protect your family from rising threats from Islamic extremists. It's starting to feel like a flashback to 2004, when Republicans built a campaign around keeping you safe, with blunt suggestions that Democrats were weak and wobbly on national security. Most of the messages are aimed at women voters, particularly those independent ones who already have lost confidence in President Obama. They are the voters Democrats need to win by large margins if the party hopes to win key races - and hold their fragile control of the Senate.

ABC's ALISA WIERSEMA: If you were wondering what a political video with virtually all of the high-profile female Republican candidates running this year would look like, you're in luck. In the party's latest appeal to women voters, the Republican National Committee released a new spot last night titled, "Women of the GOP." The ad features candidates running for House, Senate and gubernatorial seats, including Monica Wehby, Elise Stefanik, Shelley Moore Capito, Mia Love, Susana Martinez, Marilinda Garcia, Terri Lynn Land, Martha McSally, and Joni Ernst. In the ad Wehby is touring a factory in a hard hat; McSally is running through a desert; and Love is working with machinery that is labeled "flammable." "We're the take the initiative party; the party that won't give up because this election is too important. There's too much at stake," a woman narrator says in the video. "This year, Republican women are taking back the future." WATCH: http://youtu.be/mJrrFNdNOn0

14 FOR 14: THE MIDTERM MINUTE

-LOUISIANA: LANDRIEU'S OCTOBER SURPRISE. With less than a month before Election Day, Sen. Mary Landrieu has replaced her campaign manager and is bringing long-time trusted advisers on board. Adam Sullivan is being replaced as campaign manager with Ryan Berni, who has long served as an aide to Landrieu's brother Mitch in his role as the mayor of New Orleans. In a statement to ABC News, campaign spokesman Fabien Levy downplayed the changes: "As Senator Landrieu has done in all of her races, she is bringing on some of her long-time and trusted advisers to assist during the last month of the race to lead us to victory on November 4. Adam Sullivan will remain a senior adviser to the campaign." -Jordyn Phelps

-KENTUCKY: MITCH MCCONNELL GETS TESTY WITH KENTUCKY SPORTS RADIO. Mitch McConnell had a sometimes contentious interview on Kentucky Sports Radio Wednesday, sharing some testy exchanges with the host Matt Jones. He asked the Senate Minority Leader several times why he won't agree to a debate with his Democratic challenger Alison Lundergan Grimes on the show, which she has agreed to. McConnell called the host an "Obama enthusiast" and the sharpest exchange took place when Jones asked McConnell twice if he believes in climate change. McConnell snap back at Jones the second time saying, "It is not a yes or no question, I am not a scientist!" Once it was over, Jones made clear he didn't think McConnell was on his best behavior telling another host he was "unnecessarily combative" and said he "came across as a little bit of a jerk." LISTEN: http://bit.ly/1o15r17 - Shushannah Walshe

WHAT WE'RE WATCHING

WHEN POLITICS WENT TABLOID: REPORTER MATT BAI SAYS IT BEGAN WITH THE 1987 DOWNFALL OF GARY HART. For as long as there has been politics, there have been sex scandals. But what is new, Yahoo political columnist Matt Bai writes in a new book "All the Truth is Out: The Week Politics Went Tabloid," is the media's tabloid-style obsession with the personal lives of our political leaders - an obsession that he argues has resulted in the corruption of modern political reporting. Bai traces the beginning of the tabloid-style era of political reporting to 1987, when the campaign for Democratic presidential candidate Gary Hart, whom Bai describes as the "Hillary Clinton of his moment," fell apart after reports surfaced that he was having an extramarital affair. "It unravels in the kind of scandal and sensationalism that had never existed in presidential politics before that moment," Bai told ABC's JONATHAN KARL in a "Politics Confidential" interview. http://yhoo.it/1sfh4Rx

THE BUZZ with ABC's KIRSTEN APPLETON

HAPPENING TODAY: OBAMA GOES WEST. President Obama heads out West today for three days of official and fundraising events. He kicks things off in Los Angeles with an appeal to millennials, according to ABC's MARY BRUCE. He will outline his agenda to create economic opportunity for young Americans during a visit with young professional and entrepreneurs in Santa Monica. The event is part of a broader effort by the White House to get the attention of this key demographic ahead of the midterms. Then the president is off to shake the money tree, attending a fundraiser for Democratic candidates hosted by actress Gwyneth Paltrow. The Oscar winner is opening her home for an intimate dinner and reception for deep-pocket donors.

THE TED CRUZ EFFECT: CAN HE SWAY A SENATE RACE? It's been one year since the 16-day government shutdown. At the time, it was a move that appeared to work in favor of Democrats eager to paint figures like Sen. Ted Cruz and other Republicans as obstructionists favoring brinksmanship over compromise. But times have changed, and now Cruz, R-Texas, is set to spend part of the anniversary of the shutdown in Kansas, helping out endangered Sen. Pat Roberts, the three-term incumbent who faces his toughest challenge yet against an Independent candidate preaching centrism. Today Cruz will join Roberts in the kick-off of a four-day bus tour along with retiring Oklahoma Sen. Tom Coburn, ABC's ALEXANDER MALLIN reports. "I am proud to call Pat Roberts a friend and to endorse him in this important race for U.S. Senate," Cruz said in a statement released by the campaign. "One year ago, Pat stood by my side in the fight to defund Obamacare, and he will continue to fight against intrusive liberal policies in the U.S. Senate." http://abcn.ws/1y8988d

DHS REBUFFS CONGRESSMAN'S CLAIM ISIS INFILTRATING SOUTHERN BORDER. ABC's JOHN PARKINSON reports the Department of Homeland Security yesterday denied a congressman's assertion that fighters with the militant group Islamic State, also known as ISIL or ISIS, have been caught crossing the southwestern border. "The suggestion that individuals who have ties to ISIL have been apprehended at the Southwest border is categorically false, and not supported by any credible intelligence or the facts on the ground," a DHS spokesman said in a statement. "DHS continues to have no credible intelligence to suggest terrorist organizations are actively plotting to cross the southwest border." Rep. Duncan Hunter, R-Calif., told Fox News on Tuesday night that ISIS is sneaking into the U.S. through the southwestern border. "I know that at least ten ISIS fighters have been caught coming across the Mexican border in Texas," Hunter claimed. "There's nobody talking about it." http://abcn.ws/1uCObj6

A HAIRY QUESTION FOR THE SUPREME COURT: SHOULD PRISONERS BE ABLE TO GROW BEARDS? Justice Samuel Alito, joined by some of his colleagues, had little patience on Tuesday for the arguments of a lawyer defending the Arkansas Department of Corrections "no beard" policy. ABC's ARIANE DE VOGUE reports the policy is being challenged by an inmate, Gregory Holt, who argues that his Muslim faith requires him to grow a beard. He says he would be happy with a half-inch beard, but prison policy allows a one-fourth inch beard only for inmates with dermatological problems. Holt says the prison policy violates his rights under a federal law specifically designed to protect religious exercise for prisoners. In court, David A. Curran, Arkansas Deputy Attorney General, told the justices that they should give deference to the prison's security objectives, and that a half-inch beard could be used by an inmate to "alter his appearance, thwart identification, and conceal contraband." http://abcn.ws/1oRWRfX

IN CASE YOU MISSED IT

FUSION'S MASSIVE MILLENNIAL POLL. A poll released by Fusion today is the largest survey completed in the 2014 midterm election cycle focused on millennial voters. It offers new insights into how one of the political world's most coveted - and least predictable - voting block might shape the outcome of this year's midterms. According to FUSION, an ABC/Univision joint venture, Millennial voters like Hillary and Paul Ryan for 2016. In the midterm elections, the majority will give Republican candidates a thumbs down. And in the wake of Ferguson, a majority of young voters oppose the militarization of police. http://fus.in/1v4VEsG

WHY A BEAUTIFUL HAWAIIAN BEACH WON'T BE NAMED AFTER OBAMA. But for a public outcry, President Obama could have spent some of his retirement soaking up rays and catching waves at a popular beach in Honolulu named in his honor. According to ABC's VERONICA STRACQUALURSI, a plan to rename one of the president's favorite beaches came to a screeching halt this week. Honolulu city council members rejected a resolution that would have renamed Sandy Beach Park to President Barack Obama Sandy Beach Park because native Hawaiians were concerned that the name change would encroach on the beach's cultural and historical significance and flood it with more tourists. Mark Segami, a spokesman for the Honolulu City Council, told ABC News that the council is now considering naming a rail stop in downtown Honolulu after the president, since he is a huge supporter of the rail transit project. http://abcn.ws/1seMed0

WHO'S TWEETING?

@PostReid: Healthcare dot gov won't show premiums for 2015 until 2nd week of Nov., AFTER the midterms. http://tbo.com/news/politics/next-edition-of-healthcaregov-is-unveiled-20141008/ …

@JohnCelock: . @PatRoberts2014 tells @JosephAshbyShow he's been in more Kansas communities than any pol including Bob Dole. #kssen #kseln #ksleg

@politicoalex: Bosnich says former boss @carldemaio harassed, intimidated, and then tried to give him $50k to stay quiet http://politi.co/1oSMMzk

@nationaljournal: Some Democrats now see value in turning against Nancy Pelosi http://bit.ly/1o03YYT

@ryanstruyk: New CNN poll this morning in Alaska (don't see many good polls out there…) and it's bad news for Begich: Sullivan up 50 (!) to 44. #AKSen