There has been a steep drop in Obamacare insurance numbers, halfway through the sign-up season for 2019, raising concerns that the Trump administration’s controversial policy changes are undermining the marketplaces. The 9.2 percent drop to roughly 100,000 sign-ups per day has surprised close observers of the Obamacare markets, who expected the number of customers to remain fairly stable even after Republicans eliminated the unpopular individual mandate penalties for being uninsured.