Democratic presidential contenders Hillary Clinton and Bernie Sanders will face off Thursday night at 9 pm EDT in a critical debate ahead of the April 19 New York primary.CNN says the debate in Brooklyn—the fifth one-on-one between Sanders and Clinton, but the first since Miami on March 9th—\u0022could be the feistiest yet.\u0022#DemDebate TweetsAs NPR\u0026#039;s Tamara Keith noted Thursday, in the lead-up to debates, \u0022it sometimes seems like candidates are planting bread crumbs hoping the moderator follows them.\u0022 She offered fracking as an example, pointing to Sanders\u0026#039; recently released \u0022No Fracking Anywhere\u0022 advertisement.Indeed, 350 Action predicted Thursday afternoon that \u0022fracking is expected to be front and center as [the] candidates meet in New York.\u0022The Hill reported on Wednesday that \u0022Sanders has taken a firmer line against the drilling practice than the Democratic front-runner, calling for it to be banned nationwide.\u0022 That\u0026#039;s important, the publication explained, because \u0022[a]nti-fracking forces in New York are more organized than elsewhere in the country.\u0022Meanwhile, said 350 Action spokesperson Linda Capato, Jr., \u0022Clinton has ramped up plans to tackle climate change, and yet she\u0026#039;s still referring to natural gas as a potential bridge fuel. Tonight\u0026#039;s debate will be pivotal for candidates to take strong stances against fossil fuel interests. No matter how you slice it, natural gas is a fossil fuel, and the only safe place for fossil fuels is in the ground.\u0022The candidates might also tackle the issue of nuclear power, given that the Indian Point plant is just 25 miles north of New York City. Sanders has called for the accident-prone plant to be shut down, while Clinton has called for increased oversight but not closure of the facility.Clinton is leading in recent polls of New York voters, but Sanders has been closing the gap. One recent poll showed him trailing Clinton 52-42 percent, up from 55-34 percent last month.Another issue that is likely to come up on Thursday night is gun control. The Washington Post reports: \u0022Clinton could also return to a familiar line of attack against Sanders: that he has been too supportive of pro-gun legislation. That argument has special resonance in New York City. Clinton has argued that Sanders, representing a mostly white, mostly rural state, has been slow to recognize the damage guns do in cities.\u0022The international NGO Global Witness, meanwhile, is calling for all presidential candidates to \u0022publicly address the widespread problem of secret companies in the U.S. and corruption exposed in the Panama Papers and outline their own plans for reform.\u0022Indeed, given their location near the global hub of finance, Clinton\u0026#039;s Wall Street ties and the matter of \u0022too big to fail\u0022 banks are also likely to arise.And CNN suggests that President Barack Obama\u0026#039;s admission this week—that the 2011 U.S.-backed toppling of Libyan dictator Muammar Gaddafi was his \u0022worst mistake\u0022—might find its way into Thursday\u0026#039;s discussion.\u0022Sanders, for his part, has more broadly targeted Clinton\u0026#039;s views on regime change,\u0022\u0026nbsp;CNN\u0026nbsp;reports. \u0022This tension could resurface Thursday night if Clinton chooses to defend Obama administration\u0026#039;s engagement in Libya.\u0022Following Thursday night\u0026#039;s debate, Sanders will leave the U.S. for two days to appear at an academic conference at the Vatican devoted to themes of economic and social justice.Meanwhile, Clinton is also leaving New York on Friday, for a high-rolling fundraiser hosted by George Clooney and his wife, human rights attorney Amal Clooney.