No, Obama is not the Antichrist. The Antichrist had already come in the Apostle Paul's day, for he said that the 'Mystery of Iniquity' had already begun to work.
Martin Luther told us who the Antichrist is, and why. He cites the book of Daniel:
"They allege the Sabbath changed into Sunday, the Lord's day, contrary to the Decalogue, as it appear, neither is there any example more boasted of than the changing of the Sabbath day. Great, they say, is the power and authority of the church, since it dispensed with one of the Ten Commandments." Martin Luther, Augsburg Confession of Faith, art. 28.
“I hope that the last day is at the door. Things could not become worse than the Roman see makes it. It suppresses the commandments of God, it exalts its own commandments above God’s. If this is not Antichrist, then some one else must tell what it is.” - “Luther’s Reformatory Works,” p. 280. Copenhagen: 1883.
Even Philip Melanchthon, Martin Luther's companion in the Reformation, on the prophecy on Daniel 7:25, declared:
"He [the papal Little Horn] changeth the tymes and lawes that any of the sixe worke dayes commanded of God will make them unholy and idle dayes when he lyste, or of their owne holy dayes abolished make worke dayes agen, or when they changed ye Saterday into Sondaye. . . . They have changed God's lawes and turned them into their owne traditions to be kept above God's precepts."—Exposition of Daniel the Prophete (1545), tr. by George Joye, p. 119.
It was the changing of the 10 Commandment Law of God that makes someone the Antichrist. The Catholic Church admits to doing just that.
The Bible Says: "He shall speak great words... and think to change times and laws." Daniel 7:25
Father James A. O'Brien: "That observance [of Sunday instead of Saturday] remains as
a reminder of the Mother Church from which the non-Catholic sects broke away."1
1The Faith of Millions (Huntington, IN: Our Sunday Visitor, Inc., 1974), p. 401.
"The Bible says, Remember that thou keep holy the Sabbath day. The Catholic church
says, No! By my divine power I abolish the Sabbath day, and command you to keep the
first day of the week. And lo, the entire civilized world bows down in reverent
obedience to the command of the holy Catholic church!" Father Enright, C.S.S.R. of
the Redemptoral College, Kansas City, History of the Sabbath, p. 802
“You may read the Bible from Genesis to Revelation, and you will not find a single
line authorizing the sanctification of Sunday. The Scriptures enforce the religious
observance of Saturday, a day which we never sanctified.” James Cardinal Gibbons,
The Faith of Our Fathers (1917 ed.), pages 72, 73.
“If Protestants would follow the Bible, they should worship God on the Sabbath Day
(Saturday). In keeping the Sunday they are following a law of the Catholic Church.”
Albert Smith, chancellor of the Archdiocese of Baltimore, Feb. 10, 1920.
“The observance of Sunday by the Protestants is an homage they pay, in spite of
themselves, to the authority of the Catholic church.” Monsignor Louis Segur, Plain
Talk About the Protestantism of Today (1868).
"SUNDAY is our MARK of authority. . . . The church is ABOVE the Bible, and this
transference of Sabbath observance is proof of that fact.”—Catholic Record,
September 1, 1923.
"Of course the Catholic Church claims that the change (Saturday Sabbath to Sunday)
was her act... And the act is a MARK of her ecclesiastical authority in religious
things." H.F. Thomas, Chancellor of Cardinal Gibbons