Peyton Manning and the Republican Primary: Knowing When It’s Time to Quit by Geoff Colvin @FortuneMagazine March 7, 2016, 10:36 AM EDT E-mail Tweet Facebook Linkedin Share icons Winners never quit and quitters never win, say some motivational speakers, but that’s a poor message for leaders. In real life, the best leaders know there are inevitably times when the wisest move is to step down, step back, or tactically retreat. Look at who’s wrestling with those issues right now. -The most urgent strategic issue for anti-Trump Republicans is whether it’s smarter to fight him with three challengers or one. He has succeeded so far only because his opposition is splintered. On Super Tuesday, for example, his average share of the vote was just 35%; but the 65% who want someone else split their support among four challengers, so Trump finished first. You can’t help noticing that in the four primaries and caucuses on Saturday after one of those challengers, Ben Carson, dropped out, Trump won only two and Ted Cruz won two. Should John Kasich now drop out ASAP, and maybe even Cruz or Marco Rubio, so Trump’s opposition can consolidate its majority? Or, as Mitt Romney argued last week, should the three remaining challengers all do their best so that no one enters the convention with a majority of delegates? For three of the remaining four, deciding when to drop out will be their most important leadership decision of the campaign. Sign up for Power Sheet, Fortune’s daily morning newsletter on leaders and leadership. -Several retail CEOs have made the painful decision to close stores, clearly the right move when the industry is being turned inside out (and when today’s or yesterday’s company leaders didn’t get ahead of the trends). Walmart’s Doug McMillon will close 269 worldwide; J.C. Penney’s Marvin Ellison, 40; Macy’s Terry Lundgren, 25 to 40; Target’s Brian Cornell, 23. Retailers hate doing this, but smart CEOs know that lowering the company’s breakeven point and living to fight another day is a decision best not delayed. -Should Britain drop out of the European Union? Prime Minister David Cameron and many of Britain’s top CEOs think not; London Mayor Boris Johnson and many other business leaders think it should. Johnson made his case for leaving on the BBC on Sunday; Bank of England Governor Mark Carney will presumably argue for staying when he testifies to Parliament on Tuesday. The nation will decide in a June 23 referendum. To argue for Brexit is to give up on the brilliant future that Conservative PM Edward Heath promised when the U.K. joined the Common Market, as it then was known, in 1973. But plenty of leaders, include many Conservatives, now think it’s best. -The outstanding departure of the week will likely be Peyton Manning’s announcement on Monday that he’s retiring from football. The decision seems obvious. At age 39, after 18 seasons, coming off his second Super Bowl win, holding a yard-long list of league records, universally hailed as one of the sport’s all-time greats, he had nothing left to accomplish. But even if the move was obvious, we shouldn’t assume it was easy. For leaders, saying goodbye is never easy, even when it’s the right thing.