WASHINGTON — Senator Rand Paul of Kentucky did not come to this town to be quiet.

In the first six months of his tenure, he has designed his own budget (something, point of fact, that Senate Democrats have not accomplished), flirted with running for president and tormented Obama administration officials at a hearing over the fact that his toilets, hampered by federal water-use regulations, do not function properly.

This week, Mr. Paul’s parliamentary maneuvers nearly caused the Patriot Act to expire, and forced hundreds of colleagues in both chambers of Congress to reconsider their travel plans before a holiday weekend so he could fight for amendments to that bill.

In so doing, Mr. Paul, a Republican, managed to enrage Senator Harry Reid, the Democratic majority leader, who suggested on the floor of the Senate that Mr. Paul might not mind if terrorists get armed to the teeth. Nor did he thrill Senator Mitch McConnell, the Republican minority leader and fellow Kentuckian, when he urged supporters to contact Mr. McConnell’s office with a message to get out of Mr. Paul’s way.

A senatorial peacock with a rust-colored crown, Mr. Paul stands out as someone who, at least for now, seems to be here less to make laws than points. His libertarian-leaning amendments — one would have made it harder for counterterrorism investigators to obtain firearms records and another would have relieved banks from their duty to report suspicious transactions — failed by wide margins, even among Republicans.