a filibuster
... that Senator Chris Murphy launched a filibuster in the United States Senate promising to hold the floor "for as long as I can", or until Congress acted on gun control legislation?
... that <a class="mw-redirect" href="./Senator" id="mwCNg" rel="mw:WikiLink" title="Senator">Senator</a> <a class="mw-redirect" href="./Chris_Murphy_(Connecticut_politician)" id="mwCNk" rel="mw:WikiLink" title="Chris Murphy (Connecticut politician)">Chris Murphy</a> launched <b id="mwCNo"><a href="./Chris_Murphy_gun_control_filibuster" id="mwCNs" rel="mw:WikiLink" title="Chris Murphy gun control filibuster">a filibuster</a></b> in the <a href="./United_States_Senate" id="mwCNw" rel="mw:WikiLink" title="United States Senate">United States Senate</a> promising to hold the floor "for as long as I can", or until Congress acted on <a href="./Gun_control" id="mwCN0" rel="mw:WikiLink" title="Gun control">gun control legislation</a>?