In May 2006, Van Hollen formed a congressional caucus on the Netherlands with Dutch-born Republican U.S. Representative Pete Hoekstra from Michigan. The goal of the caucus is to promote the U.S. relationship with the Netherlands and remember the Dutch role in establishing the State of New York and the United States. In July 2006, Van Hollen urged the Bush administration to support a ceasefire supported by a peacekeeping force that would end the 2006 Lebanon War. He was criticized by elements of the Jewish and pro-Israel community, a large part of his constituency, for criticizing U.S. and Israeli policy in the Lebanon conflict. In follow-up comments, Van Hollen indicated that his original comments were meant as a critique of Bush administration policy but did not retract his position, and other members of the local Jewish and pro-Israel community defended him. In 2006, Van Hollen opted out of the race to succeed the retiring Senator Paul Sarbanes, saying he would rather spend time with his family and help elect more Democrats to Congress. In keeping with that, Van Hollen was appointed to Chairman of the Democratic Congressional Campaign Committee. In 2009, Van Hollen introduced a bill which establishes a green bank to catalyze the financing of clean energy and energy efficiency projects. He reintroduced the same bill again in 2014. In March 2010, when Charles Rangel was forced to resign as Chairman of the Committee on Ways and Means over ethics charges, Van Hollen played a key role in having Sander Levin succeed to the Chairmanship over Pete Stark. Stark was the second-most experienced member of the committee while Levin was third, and party tradition would have made Stark chairman due to seniority. However, Van Hollen and other younger members saw Stark's past intemperate comments as a liability to the Democrats in an election year. On April 29, 2010, Van Hollen introduced the campaign finance DISCLOSE Act. He reintroduced the bill for the 113th Congress on February 9, 2012. In April 2011, Van Hollen sued the Federal Election Commission, charging it with regulatory capture and the creation of a loophole that allowed unlimited and undisclosed financing in the 2010 election season. According to Van Hollen, had it not been for the loophole, "much of the more than $135 million in secret contributions that funded expenditures would have been disclosed." Shortly after the 2016 elections, Van Hollen was selected as the Chairman of the Democratic Senatorial Campaign Committee (DSCC) for the 2018 cycle. Caucus membership  Prior to Van Hollen's election, incumbent Connie Morella had won eight elections in the district, despite the fact that she was a Republican in a district that had swung heavily Democratic.