Sen. Rand Paul delivers remarks at CPAC that are centered around the ongoing budget battles in Washington.

OXON HILL, Md. -- Rand Paul had tough words for his own party, describing it as “stale and moss covered” before conservatives at the Conservative Political Action Conference.

“The Republican Party has to change by going forward to the classical and timeless ideas enshrined in our Constitution,” the Kentucky senator said here. He added, “We need a Republican Party that shows up on the Southside of Chicago and shouts at the top of our lungs 'We are the party of jobs and opportunity. The GOP is the ticket to the middle class.' The GOP of old has grown stale and moss-covered. I don't think we need to name any names here, do we?”

The critique of the GOP received resounding applause from this crowd, but the reception for Paul, whose tone could be described as solemn, wasn’t full-throated. His speech, in fact, highlighted the difficulty he would face if he were to make an expected 2016 run.

Paul, the heir to his father Ron’s “torch of liberty,” tried here to straddle the line between his staunch libertarianism -- which includes dovish views on foreign policy, privacy rights and even drug use -- with his conservative line on spending that principally makes him a darling of these activists.

Many here praised Paul for his modern-era record 13-hour filibuster. But not all did so on the substance.

“I have a message for the President, a message that is loud and clear, a message that doesn't mince words,” Paul began.

“Don't drone me, bro!” interrupted one young supporter.

The crowd laughed; Paul leaned back, took it in, and joked that that was not exactly the message.

But Paul only received tepid applause as he made his way through the opening section of his speech about civil liberties and drone use. Paul has raised questions about the administration’s contention that drones could be used against Americans acting as enemy combatants on American soil.

“Good intentions are not enough,” Paul said was his message for President Barack Obama. There were just a smattering of applause.

“If we allow one man to charge Americans as enemy combatants and indefinitely detain or drone them, then what exactly is it our brave young men and women are fighting for?” Paul said, and again just tepid applause.

“Our Bill of Rights is what defines us and makes us exceptional,” Paul said to polite applause.

On reaching out to youth, Paul said, “They want leaders that won't feed them a line of crap or sell them short. They aren't afraid of individual liberty.” Just a light round of claps.

Paul was much better received when criticizing the president for spending, taxes, the sequester, and cutting foreign aid and waste – instead of White House tours.

“The only stimulus ever proven to work is leaving more money in the hands of those who earned it!” Paul said.

“Only in Washington could an increase of $7 trillion in spending over a decade be called a cut,” Paul said of the sequester. And added to raucous applause: “Meanwhile the President found an extra $250 million to send to Egypt. … I say-not a penny more to countries that burn our flag.”

Paul contended that instead of eliminating White House tours, he should cut research for “monkeys on meth,” robotic squirrels, and menus for colonization on Mars that were developed by college students given all-expense paid trips to Hawaii.

“Mr. President, maybe we could have cut robotic squirrels before White House tours,” Paul said.