Before conservatives line up to support Donald Trump they should check his record, cautions FreedomWorks CEO Adam Brandon.

FreedomWorks is an influential conservative organization that has successfully mobilized activists to support small-government candidates and causes.

"Let's take him [Trump] seriously for a second: He has said he is for socialized medicine, single-payer healthcare," Brandon told the Washington Examiner. "I know for the last several years FreedomWorks activists have fought tirelessly against Obamacare, and Obamacare looks like a free market solution compared to what Donald Trump has said in the past he would like to see in our healthcare system. So to me that's almost like a, just a no-go."

"As a movement we would look silly if we spent all this time, treasure, energy fighting Obamacare and then we decided to nominate someone who's basically going to let the federal government take the entire system over."

Brandon also expressed concerns about Trump's past support for various big government proposals, including tax increases, but is not worried about Trump spoiling the party just yet.

"If I was running for office right now and I was leading the Republican field, based on a lot of history, this is not the time [to lead the polls]," he said. "We're not even in the beginning of the first quarter, I don't even know if the game's even started yet to be honest."

FreedomWorks has no plans to endorse any particular presidential candidate, but when things do heat up it will work to help shape the debate, Brandon said. He wants to make sure the GOP nominee puts forward a "very robust [and] detailed economic agenda."

Other Tea Party-minded activists have begun to speak out against Trump, too. Sal Russo, a former adviser to Ross Perot's presidential campaign, told the Examiner's David Drucker that Trump's message lacks seriousness and the uplifting vision necessary to win elections. Despite Trump's controversial comments and antics, he remains near the top of many polls, and finished in first place in a Washington Post/ABC News poll released earlier this week.