Mitt Romney may have all but locked up the Republican nomination with his victories in the East Coast primaries this week, but Ron Paul and his army of acolytes aren't ready to give up the fight just yet. 

As the rest of the political world's attention shifts to the general election, Paul is still quietly amassing delegates at district and county conventions, and is now poised to take a real bite — or at least a big nibble — out of Romney's delegate total. 

In just the last week, Paul locked up 49 delegates, including five in Pennsylvania and four in Rhode Island, two states thought to be firmly on Romney's turf. In Minnesota, Paul won 20 of the 24 delegates awarded at last weekend's district caucuses, an impressive sweep that guarantees that Paul will control a majority of the state's delegation at the Republican National Convention. 

And despite staunch opposition from the state Republican Party, Paul took 20 of the 40 delegates awarded in Missouri last weekend, according to campaign chairman Jesse Benton. 

In at least five other states — Colorado, Nevada, Iowa, Washington, and Maine — Paul has done remarkably well at county and district conventions, and his supporters are expected to win a big chunk of the RNC delegates at the state conventions later this spring. 

"We are very pleased with the results," Benton told Business Insider. "We still have a long way to go, but we've done very, very well at the county caucuses and district conventions and that bodes well for our strength when we get to the state conventions. Now we need to keep our nose to the grindstone." 

Even Rick Santorum, who earlier in the race accused Paul of shilling for Romney, acknowledged the Texas Congressman's impressive organization this week, telling CNN's Piers Morgan that "Ron Paul is working the delegates hard." 

In a surprising twist, a lot of Paul's recent success can actually be attributed to Santorum's decision to suspend his campaign earlier this month. In many places, Santorum supporters have banded together with Paul organizers in an attempt to deny Romney delegates. 

In Colorado, for example, Santorum supporters have bonded with their Paul counterparts over a shared skepticism of Romney's conservative values. Although the Colorado GOP won't select its RNC delegates until the state convention next month, Paul organizers have gotten many of Santorum's pledged delegates to commit to supporting Paul over Romney. 

"In Colorado, there is a real anti-Establishment sense — they want to send a very conservative delegation to the national convention," Benton told BI. "We're fighting it out, and we think there are enough Santorum delegates that are sympathetic to Ron Paul who will come over to us."