In soccer, it’s called scoring an “own goal” when your team accidentally puts the ball in its own net. Sen. Rand Paul (R-KY) hopes Senate liberals have just done exactly that this week.

Senators were considering a bill to approve the building of the Keystone XL pipeline. In the course of debate, they voted on a total of 15 amendments to the bill.

One amendment stands out.

Proposed by Sens. Robert Menendez (D-NJ) and Maria Cantwell (D-WA), it was aimed at creating what Menendez in a news release called “a new ‘Private Property Protection’ that would prevent a foreign company from seizing private property to build the Keystone Pipeline unless the landowner is willing to sell.”

Sen. Paul is one of only two Republicans (Kelly Ayotte of New Hampshire is the other) to vote for that amendment. He tells Breitbart News in an exclusive interview that he favors building the Keystone XL pipeline, but that he’s even more concerned with protecting private property rights. And he’s pleased that so many Democrats – who voted 39-4 for the amendment – agree.

“Unless the Democrats were just playing games, they just voted to strengthen property rights,” Paul says.

This all harkens back to the Supreme Court’s decision in the 2005 case Kelo v. City of New London. In that case, the justices held a city could use eminent domain to take land from a property owner and give it to another as long as that transfer gives economic benefits to the community.

“Kelo is one of the worst Supreme Court cases of the last 50 years,” Paul says. “This was a vote against Kelo.” He hints he may introduce a stand-alone measure to overturn Kelo, especially since such a bill would seem to enjoy such deep Democratic support.

The process also highlights important changes in Senate procedure. The fact that opposition senators were allowed to propose amendments marks a refreshing change from recent years, and seems to be a return to the “regular order” that Majority Leader Mitch McConnell promised last year.

“We’ve had more votes this year than last year,” Paul said. “The minority will feel more empowered if they get to vote on things. We showed we were willing to take their amendments. It was Democrats who were slow-walking this bill.”

The 2015 Senate session is barely underway, of course, but many senators are already looking ahead to 2016. On Friday, Sen. Marco Rubio (R-FL) told his aides to proceed as if he’s running for president, even though he hasn’t made a final decision.

Paul says he’s also weighing a run. “What I want to know is: Is my message resonating?” If he decides it is, Paul says there’s a good chance he’ll run for president. He adds he expects to make a decision soon – probably by March or April.