If you watched the above video, you heard Raylan Alleman of Fix the Family read the anathema of the Papal Encyclical Casti Connubi of Pius XI (1930), which states that no Catholic can get divorced and remarried.
Divorce in itself is a sin, as stated by Jesus Christ in the Gospels. It is adultery, a mortal sin.
However, most Novus Ordo Catholics think that obtaining an annulment from the Church after the decree of a civil divorce in order to marry someone else is satisfactory as a "Catholic Divorce": it is not. An annulment (in the traditional Church) can only be granted if the two parties did not meet the requirements for marriage the moment they take their vows. Some examples include:
- One of the parties is not baptized and confirmed.
- The parties are second cousins.
- One of the parties does not meet the minimum age requirement (ecclesiastically this is 16 for men and 14 for women, but in many U.S. jurisdictions the minimum is 18 for both parties).
- One of the parties committed a crime against the other (e.g. rape, fortification, cohabitation, incest, abuduction, or any other sexual assaults).
- This marriage was not contracted freely without mental reservation.
- The marriage ceremony was not contracted before a validly ordained priest using the ceremony as described in the Roman Ritual.
Traditionally, an annulment would not be granted if you cheated on your spouse and get divorced civilly, which is the case today, where annulments are granted for for silly reasons like alcoholism, drug addictions, or not taking care of the kids, non of which are impediments to marriage.
An annulment is not the same as a Catholic divorce, as there is no such thing as a Catholic divorce. If for some reason you get a civil divorce and your marriage had no impediments, then you two are still married in the Church until one of you dies. Filing for divorce alone will land you in Hell, never mind remarrying when your ex is still alive.