Definition: In this task, you will be presented with a passage and have to answer a question based on your understanding of the events inferred from the passage. Try to find the best answer that is most likely to fill in "_". Note that the URLs in the text have been replaced with [Link].
Input: Working closely with the White House, the Republican-controlled House of Representatives revived President Barack Obama's trade agenda today, voting to strengthen his hand in global negotiations and clearing the way for a showdown in the Senate. The 218-208 vote marked the first step in a bipartisan rescue operation mounted in the week since labor-backed Democrats in the House - including the chamber's Democratic leader, Nancy Pelosi - rebelled against the president and derailed his trade package. In a twist of awkward timing, Pelosi is bringing the president to her San Francisco district tomorrow for his first fundraiser to benefit Democratic House candidates in the 2016 race — including many of the very lawmakers who delivered Obama a stinging defeat last week in his effort to complete trade negotiations with 11 Pacific Rim nations.The 218-208 vote marked the first step in a bipartisan rescue operation mounted in the week since labor-backed Democrats, including Nancy Pelosi - rebelled against the president and derailed his trade packageIn a twist of awkward timing, Pelosi is bringing the president to her San Francisco district tomorrow for a first fundraiser to benefit DemocratsMany of those same lawmakers delivered Obama a stinging defeat last week in his effort to complete trade negotiations with 11 other nationsIn the ramp up to the votes, Obama wined and dined Democrats; the White House says the annual picnic he hosted was just a social event, thoughHis trade agenda still needs approval from the Senate - that's a tall taskHis four-day excusrsion started today in LA; he goes to San Francisco tomorrow and Palm Beach after that 
 Question:The eruption over trade follows a 'longstanding disagreement' in the _ caucus, she further explained, and has everything to do with members' bosses - the constituents - and very little to do with Obama.

Democrats