Karl Rove accused U.S. Rep. Justin Amash, R-Cascade Township, of being the "most liberal Republican" during the Aspen Ideas Festival in late June.

(YouTube)

Justin Amash

GRAND RAPIDS, MI — Video has surfaced of GOP strategist Karl Rove calling U.S. Rep. Justin Amash, R-Cascade Township, the "most liberal Republican."

Speaking during the Aspen Ideas Festival in late June, Rove criticized Amash's reputed staunch libertarian stances on legislation as antithetical to tackling issues in Washington.

The swipe came during a June 27 panel discussion about whether to include some libertarian tenets in Republican policy, which Rove cautiously advocated.

"The most liberal Republican is Justin Amash of Michigan. Far more liberal than any other Republican," said Rove, who was senior adviser and deputy chief of staff to former President George W. Bush.

"And why? Because he is a 100 percent, purist libertarian," Rove said, "and if it's not entirely perfect, 'I'm voting with (Democratic House minority leader) Nancy Pelosi."

Amash, who has racked up various accolades from conservative think-tanks and nonprofits for being among Congress' more conservative members, subtly shot back on Twitter.

"Which House Republican votes least often with Nancy Pelosi?" he tweeted Sunday night, linking to an OpenCongress.org scoresheet showing Pelosi votes least often with him.

An Amash spokesman declined further comment.

In any case, Rove might have been mistaken altogether, having cited National Journal magazine rankings as his source.

Each year the publication ranks what could be termed as the most "liberal" Republicans.

This year, Amash was ranked as the fifth most liberal GOP congressman. The top spot actually went to Rep. Chris Gibson, R-N.Y.

Another National Journal piece from this year said that among Republicans, Amash voted least often with his own party.

Amash is known for voting against legislation he deems unconstitutional, regardless of which party is pushing a certain bill.

That propensity has drawn the ire of critics who accuse Amash of being needlessly obtuse on issues like providing aid after Superstorm Sandy ravaged the East Coast in 2012.

Supporters fiercely defend his libertarian approach to legislating, and he has garnered substantial political celebrity among more conservative elements of the GOP.

Libertarian news site Reason.com posted the Rove video Monday. The site appeared to take umbrage with his characterization of Amash.

Watch the video here:

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