America stands for the opposite of socialism. American stands for being able to pursue whatever each person wants to pursue with her own life. America stands for being able to keep the fruits of one's own labor. Knowing that the Pledge of Allegiance is giving alliance to socialism means that it is against the principles of America.
The Pledge of Allegiance gives Americans a common platform of beliefs and commitments, it does not matter if the author was influenced by socialism. It is important to have a patriotic message that binds people especially in times of trouble. Although some do not want to say "..one nation under God..." it is still a valid message for many.
No, knowing that the writing of our Pledge of Allegiance was influenced by a socialist novelist does change your opinion of it in any way. Socialism has a proud history in the United States, especially in past eras that produced workers' rights laws, overtime regulations and strong labor unions that advocated for the rights of our laborers.
I believe that if people understand and agree with the themes and statements made in the Pledge of Allegiance then it should not matter who the author was, or who the words were influenced by. The main purpose is to show pride in your country, irrespective of who has written the Pledge.