Short answer: Yes. There are a couple reasons cited as to why it was not a filibuster. However, neither disqualifies Paul’s 10-hour talk-a-thon.
Paul’s filibuster came at a somewhat odd time. NSA spying was not on the Senate floor last night. The upper chamber was still considering the trade promotion authority (TPA) bill. Since TPA was on the floor and the Patriot Act was not, some argue that Paul was delaying action on the wrong bill and therefore, his talk-a-thon does not qualify as a true filibuster.
Delaying action on unrelated bills does not disqualify a filibuster. This is a practice that happens virtually every day. Though it wasn’t the case last night, dilatory actions, like filibuster, are often used as leverage. Senators can place holds on bills and nominees, threaten to object to unanimous consent agreements, and use other dilatory actions to secure consideration, votes, or even passage of other unrelated measures. These actions, which are effective filibusters or threats to filibuster, are commonplace in the Senate and a part of what makes individual senators so powerful. So the fact Paul was attempting to extend debate on a different bill does not disqualify last night’s very long speech.
Another reason many are floating contends that Paul’s speech did not actually delay legislation. The vote to end debate on TPA was set up two days ago. In the meantime, the Senate was just killing time until the cloture vote was held today.
This also does not disqualify Paul’s filibuster. Setting up a cloture vote is necessary to overcome a filibuster. For the past 10 years the majority of cloture votes per Congress successfully cut off debate. Put differently, most filibusters fail. Majority leaders don’t tend to waste time on votes they can’t win. Meaning, on the majority of bills that are filibustered, the delay is a maximum of two days. And in most cases, that delay is built into the schedule, as the leader will make a motion to take up a bill and file a cloture petition simultaneously, effectively preempting the filibuster before debate has really begun. If a filibuster could only be called a filibuster if it delayed legislation beyond the 2-day cloture vote process, this would disqualify roughly 74% of the filibusters in the 113th Congress.
If further evidence is needed to prove that Paul’s filibuster was legitimate, today Majority Leader McConnell filed cloture on two measures to addressing the NSA surveillance programs. This wouldn’t be necessary if Paul was not filibustering the Patriot Act.
While these criticisms don’t necessarily disqualify Paul’s filibuster, they do highlight the hollow nature of the modern “talking” filibuster. The last four filibuster-talk-a-thons have doubled as publicity engagements. Today’s filibusters harkens back to a romanticized Senate tradition that simply no longer exists. The practice of physically extending debate through long-winded speeches died a long time ago when cloture became the preferred tool to end debate in the 1970s. As a result, nearly all of the recent talking filibusters occurred when the Senate was killing time until a vote on cloture was in order.
In this context it’s not surprising that the last four talking filibuster-ers are current presidential hopefuls. They use Congress’s most widely known process to grab a national platform. Yet, while today’s talking filibusters don’t match those of the 1940s, 50s, and 60s, they nonetheless fit within the frame of extending debate.
 Senators have also used holds to secure agreements from the executive branch, ensure the administration responds to an inquiry, or to signal that a negotiation on something related or unrelated needs to take place before a bill or nominee will move forward.