Perhaps the most important component in Mitt Romney’s victories thus far has been senior citizens — one of the most reliable and pro-Romney blocs around. 

They’re also one of the many demographic groups that John McCainJohn Sidney McCainFor .2 billion, taxpayers should get more than Congress’s trial balloons Overnight Defense: Pompeo lays out new Iran terms | Pentagon hints at more aggressive posture against Iran | House, Senate move on defense bill Senate GOP urges Trump administration to work closely with Congress on NAFTA MORE used to gain the 2008 nomination. 

Take, for example, Florida and its large senior-citizen population. 

In 2008, Florida’s senior voters supported McCain over Romney by 10 percent, which was McCain’s largest margin with any age group. Helpfully for McCain, it was also the primary’s biggest voting bloc. Thirty-three percent of all GOP Florida primary voters were older than 65, and with McCain’s sizable margin over Romney there, he was able to overcome his deficit with younger voters. Romney won more age groups, but McCain won bigger with the most important age group.

Fast-forward to 2012 and Romney’s big Florida win. According to Fox exit polls, Romney was strongest with voters over 65 years old, and once again, this group composed more of the voting electorate (36 percent) than any other. To be true, Romney swept all age categories in his massive win, but senior citizens formed the base of his support.

Romney’s win in New Hampshire ran along much the same lines. 

The strongest age groups for him were, according to Fox News exit polls, 50- to 64-year-olds and those 65 and older. These voters combined for a whopping 56 percent of all GOP primary voters. In 2008, they once again provided the lion’s share of votes, yet there’s an odd data point in the CNN exit poll. Romney actually beat McCain among those 65 and older. In fact, it was the only age group he won in 2008. 

Thus, in Romney’s biggest wins of 2012 (New Hampshire and Florida), he’s either doing as well as or better than McCain with senior citizens. Further, it’s important to note that his wins with this group are larger than his overall wins in the state. In other words, he over-

performs with seniors.

So what does this mean? Quite a lot, actually — some of it good, some of it bad.

The upside for Romney is that he’s performing very well with the voters who matter the most in a GOP primary. As a percentage, there are a lot more older voters in a GOP primary than in a general presidential election.

For example, in Florida, 33 percent of primary voters in the 2008 election were over 65. That number fell to just 22 percent in the general election. That same dynamic held true in state after state in the 2008 election. Older voters represented a much smaller portion of voters in the general election than in the GOP primary. 

Thus, it’s safe to conclude that older voters play a far more significant role in choosing a Republican nominee than they do in choosing a president.

Fortunately for Romney, that could get him to a general election. Unfortunately for Romney, it won’t mean much once he gets there.

According to national exit polls, voters 65 and older made up only 16 percent of the voting population in the 2008 general election. To show how inconsequential that is, even the notoriously unreliable youth vote (18- to 29-year-olds) turned out in larger numbers. Unfortunately for McCain, the 65-plus set was the only age group he won. He lost in every other age group.

The results raise a huge red flag for Romney’s general-election prospects. He’s performing strongest in the smallest general-election age group. In order to be competitive with President Obama, he’s going to have to play better than McCain did in other age groups, and thus far, nothing indicates he holds any special appeal with voters under 65. He continues to over-perform with older voters and underperform with younger ones. 

The other downside is that older voters, while reliable, tend to have less energy to become involved in the political process and aren’t likely to take advantage of social media tools as extensively as younger groups. Enthusiasm for McCain was noticeably low in the 2008 election, and it’s often noted that it’s anemic for Romney in 2012. Older voters are probably less likely to knock on doors, tweet, make phone calls or engage in other activities that can turn one supporter into many more.

Critics of Rick Santorum often claim that his appeal is too limited to play broadly in a general election. But so far, Romney has appealed strongest to the group that has the weakest influence in a general election. Romney 2012 could look a lot like McCain 2008.