Personally, I am not opposed to civil marriage within the LDS community, so long as it accords with the understanding that eventual temple sealing as the ideal is being sought out. I do understand that prophets and apostles in the past have encouraged temple marriage over civil marriage for a number of reasons.  There are several spiritual or religious reasons for this, which I will forego at this point as some may consider them subjective. Instead, let us look at more objective reasons for marrying in the temple.
First, letâ€™s make some assumptions.
1.> The studies used in the encyclopedia of Mormonism, now 20 years old, are still pretty much accurate.
2.> Being divorced is undesirable.
That said, the multiple studies of Tim Heaton (referenced by the EOM)  and his associates point out the following information for us:
divorce rate men
divorce rate women
divorce rate average
All LDS Marriages
LDS Temple Marriages
LDS Marriages outside the Temple
Here we, of course, can see that temple marriages in the US have a higher probability of lasting. However, we still do not have the complete picture, which I will now attempt to derive.
First, we need to note that of the LDS divorces outside the temple, some are interfaith marriages. It has been stated that the divorce rate among interfaith lds marriages is around 40%, the highest interfaith divorce rate in America outside of interfaith Jewish marriages.  This would mean that the divorce rate for members marrying other members outside the temple is 21%  So rather than being between 5 and 6 times as likely to get divorced, members marrying other members outside the temple are only 3 times as likely to get divorced.
However, another component needs to be studied out. The statistic for LDS temple marriages makes up 58.3% of all marriages that are entered into. This 58.3% not only includes marriages which happened within the temple, but also civil marriages which later converted into temple marriages, both of the member to member and interfaith variety. While it would be interesting to speculate what percentage of civil marriages convert to temple marriages within the lds church, and the rates of divorce for the three groups mentioned (with time distributions, of course), it does not appear that there have been any studies within this domain. However, with the high percentage of first generation members in the church (not to mention the requirement in many foreign countries for a civil marriage prior to a temple sealing), it seems consistent to guess that civil marriages converting later to temple marriages make up a significant portion of all temple marriages.
Which brings me back to where I began, in that I am not opposed to civil union prior to a temple union, in so far as it is understood that the ultimate goal is a temple union. One way to look at it is to say that if you are married civilly, you have an 80% of not getting divorced before you go to the temple at the end of the year, at which point your â€œmarriage survivalâ€ odds improve exponentially. Yes, the risks are there, but it is ultimately the job of the (hopefully mature)couple to weigh these risks and to decide whether it is better to marry and divorce or to postpone marriage to a later date. All the rest of us can do is wish well, continue to encourage christlike behavior, and teach that the temple marriage is the ultimate goal of any such union.
 Doctrinally speaking, I find nothing that leads me to believe the church has any sort of position on whether it matters if a temple union is preceded by a civil union. The main corpus of text mainly points to the idea that “just a civil union” is not enough.
 EOM article on marriage
 [Bob Mims Mormons: high conservativism, low divorce, big growth, 6 March 1999, Salt Lake Tribune] as quoted at adherents.com.
 (.40 +.21)/2 = .305