John McCain helps make the case by reminding us all that he is no Fred Thompson.
By walking away from a sure-thing second term in 2002, Thompson reinforced that populist image. He also spent the next five years outside of Washington as his party steadily lost the trust of the American public. Thompson can make the argument that he wants to be part of the solution. That's a compelling argument when paired with Thompson's conservative credentials and personal attributes.
The final piece of the Thompson puzzle is money. McCain, Romney and Giuliani have all been in the race and raising money for months (if not years), and with the pricetag for the nomination estimated at between $50 and $100 million the ability to raise millions of dollars is a huge hurdle.
Lucky for Thompson that his home state is renowned for its willingness to donate to political candidates. Beginning with Sen. Howard Baker's (R-Tenn.) run for the presidency in 1980 and with Al Gore's first run in 1988 and then both of Sen. Lamar Alexander's unsuccessful bids for national office (and don't former Sen. Bill Frist's abbreviated run), Volunteer State donors are acclimated to supporting their native sons.
We fiscal conservatives don't take kindly to Club for Growth bashing.