CP and LP confuse the purpose of an ideology with the purpose of a political party. They are related, but different ... political parties are useless if they dont unite people to garner enough for political power. pulling 1% is not political power, that's being a flea-bite on the major parties ... to get that power requires UNITY and coalition-building, but 3rd parties by their defnition are DISUNITY oriented and coalition-breaking.
CP folks are a key part of activist base in the GOP;
the freedom/free-enterprise elements are as well.
LP just breaks off that coalition.
since they confuse their purposes, they only manage to create anti-productive results.
The RP does a lot of things that many CP and LP people do not consider conservative and classic liberal. If you can keep the break less than 1% to them, you've done a fine job. You cannot and will not ever make them all vote Republican. Most likely, many simply would not vote at all if there was no 3rd party option. If nothing else, the CP and LP put at least limited checks on the RP from becoming even more liberal too quickly than they already are.