Pryor raised $1.9 million, making his the largest fundraising haul so far of Democrats facing tough reelection prospects next year. It's especially impressive since he hails from a small, poor state where fundraising dollars are hard to come by.

That number was boosted significantly by a fundraiser with Clinton early in the year that brought in $1 million. He now has $3.4 million in the bank.

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Republicans don't yet have a candidate, though national Republicans are hopeful Rep. Tom CottonThomas (Tom) Bryant CottonBipartisan senators want federal plan for sharing more info on supply chain threats On The Money: Fed officials saw rising risk of recession | Ocasio-Cortez, Cruz blast NBA for 'outrageous' response to China | Prospects dim for trade breakthrough with China Ocasio-Cortez, Ted Cruz join colleagues blasting NBA for 'outrageous' response to China MORE (R-Ark.), a freshman and favorite of both Tea Party groups and national security hawks, will jump into the race. Cotton is also a fundraising powerhouse, making Pryor's haul even more important.