OXON HILL, Md. — The Koch political network for the first time plans to intervene in GOP primaries as part of a deliberate 2020 strategy to reverse years of essentially rubber-stamping the Republican Party in general elections. Disappointed with Republicans in Congress and occasionally at odds with President Trump, the coalition of political groups overseen by Charles Koch has been re-evaluating its engagement in federal campaigns. Playing in GOP primaries to elect more like-minded Republicans to the House and Senate is key tactical adjustment the network has agreed to, with a top Koch official confirming that incumbents could be targeted...