February 26, 2015 3:10 PM EST

Sen. Ted Cruz was in his element at the Conservative Political Action Conference Thursday, throwing out tweet-sized red meat to a crowd of grassroots activists.

As he prepares for a possible run for the Republican presidential nomination, the Texas Republican stressed his conservative bona fides, arguing that primary voters should look at actions, not words.

“We all know that in a campaign every, candidate comes out and tells you, ‘I’m the most conservative guy that’s ever lived,'” Cruz said. “If you’re really a conservative you will have been in the trenches and you will bear the scars.”

“I demand action, not talk,” Cruz said.

Cruz has made a name for himself as a hardline opponent of the Obama White House, helping prompt a government shutdown in 2013 in an unsuccessful bid to defund the Affordable Care Act. His pugnacity has drawn ire from Republicans like Sens. Lindsey Graham and John McCain, who has called Cruz “wacko bird” and “crazy.” But Cruz stood by his record during his speech on Thursday, drawing applause from an audience.

“If a candidate tells you they oppose Obamacare, fantastic,” said Cruz in a reference to his 21-hour speech against the law. “But when have you stood up and fought against it?”

Cruz also is seeking to establish an ideological distance between his likely campaign and Washington DC, which he impugned for its “mendacity.”

“We need to run a populist campaign, standing for hardworking men and women,” Cruz said “We need to take the power out of Washington and bring it back to the people.”

Cruz took some pointed shots at the presumptive Democratic candidate Hillary Clinton, saying that she “embodies the corruption of Washington.” Cruz was asked in a question-and-answer session with Fox News commentator Sean Hannity after his speech to describe Bill Clinton. The Texas senator answered “youth outreach” to snickers from the crowd—a less-than-subtle reference to the Monica Lewinsky scandal during his presidency.

“What I’m trying to do more than anything else is bring a disruptive app to politics,” Cruz said.

Contact us at editors@time.com.

Read More From TIME

Related Stories