A Senate committee voted along party lines Wednesday to issue a subpoena as part of the Republican-led investigation into the Ukrainian energy firm that hired former Vice President Joe Biden's son, Hunter Biden. The subpoena is one of several steps Senate Republicans are taking to ramp up probes related to the Obama administration and Biden, the presumptive Democratic presidential nominee who will likely challenge President Donald Trump in the 2020 election. The Senate Homeland Security and Governmental Affairs Committee voted 8-6 to authorize the subpoena Chairman Ron Johnson requested for Blue Star Strategies, a US public affairs firm that worked...