On March 23, 2015, U.S. Senator Ted Cruz announced his candidacy for President of the United States, prompting some political analysts to compare Cruz's support with Paul's, stating that they are both vying for the anti-establishment wing of the party. Shortly before Cruz's announcement, Paul made it clear to supporters and members of the media that he would be making an announcement on April 7, at the Galt House Hotel in Louisville regarding the 2016 presidential election, and would follow up his announcement with a four state tour of various early primary states, including Iowa, New Hampshire, South Carolina and Nevada. Pre-primary campaign developments Going into the summer, Paul hosted several town halls, meet and greets, and rallies in early states and other important states for fundraising, and voter contacts. On May 11, Paul returned to New Hampshire and held a town hall meeting in Londonderry, along with several dozen lawmakers who endorsed his campaign, and continued his campaign swing to southeastern Iowa, concluding with a "cattle call" style Lincoln dinner hosted by the Republican Party of Iowa in Des Moines. Paul also spoke outside Independence Hall in Philadelphia, and participated in a discussion at the National Constitution Center before returning to Washington, D.C. in order to tend to business in the United States Senate. Filibuster in the U.S. Senate The week before Memorial Day, he announced his intention to block any attempt at renewing the Patriot Act, in which certain provisions regarding warrantless surveillance of Americans were set to expire at the end of the month. In order to accomplish this, Paul began to filibuster the legislation on May 20, 2015, and spoke for approximately 10 and a half hours. His campaign utilized social media in order to promote the Senator's campaign, using the hashtag "Stand With Rand," which was introduced during Paul's previous filibuster. Following his filibuster, the Senate attempted to move forward with the legislation, holding a series of votes shortly after midnight on the Saturday before Memorial Day weekend, which failed to get the 3/5 supermajority needed to invoke cloture. Paul objected to all further attempts to extend the Patriot Act's provisions which had been put forth by Majority Leader Mitch McConnell (requiring unanimous consent), causing them to delay debate of the legislation until the following week. Campaign Announcement of candidacy Paul officially announced his presidential candidacy for the Republican party on April 7, 2015 at