Not really. A very Conservative voter might stay home on election day. And also, you must consider the ACORN factor.
Voter fraud and buying votes.
I doubt any conservative in the US stayed home in 2004.
In 2006, a lot of conservatives didn’t bother to vote, and it gave us Pelosi and Reid (an utter disaster).
Turnout does matter, that is why 2004 was so telling. 2006 should have been the wake up call to anyone that considers themselves a conservative sitting out an election.