The RNC letter evoked an angry response from a Nevada Secretary of State Ross Miller, who called the RNC claims "irresponsible" and "unfortunate," and said that they are based on rumor, hearsay and unconfirmed media reports.

"Unfortunately your letter fails to provide any direct evidence that any particular voter in Nevada experienced any 'errors' with their voting machines or any details which could be used to open an investigation," Miller wrote in a letter to RNC officials.

Miller said the RNC letter didn't identity any affected voters whose votes were allegedly miscast, or any polling place where the errors allegedly occurred.

So far, he said, the state has not received a single complaint from early voters regarding their use of electronic voting machines.

Miller contended that it's "technically impossible" to pre-program e-voting machines in Nevada to vote for a specific candidate. The machines are tested by officials in each of the state's 17 counties, he noted.