You can find the 63 pages of opinions here.
This is a big blow both politically to Democrats (who would have gotten a boost from the restoration of voting rights to felons who had secured their sentences) as well as to the cause of felon reenfranchisement generally.
This decision is based upon interpretation of the Va Constitution, and there does not seem to be a path to the U.S. Supreme Court (not that there would be a majority to overturn this is any case). Much of the opinions are a debate about standing. Here is the money quote from the majority on the merits;
The assertion that a Virginia Governor has the power to grant blanket, group pardons is irreconcilable with the specific requirement in Article V, Section 12 that the Governor communicate to the General Assembly the “particulars of every case” and state his “reasons” for each pardon. This requirement implies a specificity and particularity wholly lacking in a blanket, group pardon of a host of unnamed and, to some extent, still unknown number of convicted felons. No such requirement exists in the United States Constitution, and thus, the text of Article V, Section 12 of the Constitution of Virginia undermines the Governor’s argument by analogy.
From one of the two dissents:
The merits of this case do not concern the issue of whether the Governor has done 18 something he has no right to do, but rather whether he has done what he has a right to do in an 19 unconstitutional manner. Indeed, it is particularly telling that the majority does not dispute the 20 fact that the Governor may remove an individual felon’s political disabilities for any reason he chooses, including that he has served his sentence. Moreover, the majority acknowledges that the Governor could use many individual orders to achieve the mass restoration of rights he sought to accomplish under the Executive Order. Thus, the majority, in essence, takes the position that the Suspension Clause requires the Governor to exercise his executive powers in a different, less efficient manner.
[This post has been updated]