Halfway through 2015, the cable news trends seen in January have yet to shift. CNN remains much-improved from 2014. No. 1 Fox News Channel is enjoying its biggest gains in primetime, and MNSBC’s ratings slide is continuing. All this, even as political coverage heats up with the official start of presidential campaigning. For the months of April, May and June, MSNBC ratings fell 18 percent in the primetime for an average 130,000 viewers in the news demo of adults 25-54. It also brought another low for flagship The Rachel Maddow Show, averaging a notch behind its Q1 ratings with an average 143,000 in the targeted age group.