- - Wednesday, December 5, 2012

Those dismissing future Republican presidential success should consider the difficulty Democrats face in maintaining Barack Obama’s coalition. For proof, look no further than John F. Kerry and Al Gore. Mr. Obama has outperformed not only John McCain and Mitt Romney, but his Democratic predecessors, too — and there are ample reasons to question whether his successors will fare as well.

Before relegating the Republican Party to the history books, we should take a look inside those books. Mr. Obama represents a break from his own party’s past, as well as America’s, having twice received a higher percentage of the presidential popular vote than any Democrat since Lyndon B. Johnson in 1964. Over that half-century, only Jimmy Carter got as much as 50 percent.

Replicating Mr. Obama’s electoral record is far from a Democratic birthright, nor are his popular margins unassailable. His 6.3 percent margin in 2008 was halved to just 3.3 percent in November. That means a swing of just 1.7 percent to Mr. Romney would have put the Republican ahead.

Exit polling since 2000 by Edison Research/Mitofsky International shows that 1.7 percent swing is easy to conjecture.

This year, Mr. Obama dominated in five important groups: Women were 53 percent of voters (55 percent supported Mr. Obama); blacks were 13 percent of voters (93 percent backed the president); Hispanics were 10 percent of voters (71 percent supported Mr. Obama); 18- to 29-year-olds were 19 percent of voters (60 percent voted for the president); and liberals were 25 percent of voters (86 percent supported Mr. Obama). This is impressive.

With the exception of female voters, however, the two previous Democratic nominees, Mr. Kerry and Mr. Gore, fell short in each of those groups — in both participation and voter-preference percentages. How short? Enough that if Mr. Obama had scored the higher total of either Mr. Kerry’s or Mr. Gore’s support in just one of those four other groups, it would have proved insufficient and given the 2012 popular vote to Mr. Romney.

Multiplying exit-polling participation percentage by preference percentage gives a good approximation of what the Kerry or Gore electoral impact would be on these groups so crucial to Mr. Obama’s victory. The average drop in support for Mr. Obama in 2012 from the higher of either Mr. Kerry or Mr. Gore among the five groups is 2.4 percent. Delete women from the calculation, and the average decline is 2.8 percent — almost enough to have allowed Mr. Romney to win by Mr. Obama’s 2012 popular vote margin.

Even the decline in votes for Mr. Obama by 18- to 29-year-olds compared to Mr. Kerry or Mr. Gore — 2.2 percent — is still more than enough to flip the popular vote to Mr. Romney. The declines in other demographics — blacks (2.4 percent), Hispanics, (2.8 percent) and liberals (3.7 percent) — are far greater.

Furthermore, vote totals for both Mr. Kerry and Mr. Gore came against George W. Bush, who hardly racked up Reagan-sized Republican margins.

The point is, there are many moving demographic pieces in presidential elections, and this certainly was the case among the groups Mr. Obama was depending on in his re-election bid. Today’s 2016 Democratic front-runners, Joseph R. Biden Jr. and Hillary Rodham Clinton, are little like Mr. Obama — just as the possible Republican front-runners, Paul Ryan, Chris Christie, Bobby Jindal and Marco Rubio, are distinct from Mr. Romney and Mr. McCain.

It is not just candidates who change rapidly. Issues and campaign organizations do as well. Democrats had a distinct campaign spending advantage in 2008. By 2012, Republicans and conservative outside groups had outspent them.

Republicans also retain a real ideological advantage. Exit polling showed conservatives made up 35 percent of voters in 2012 and went 82 percent for Mr. Romney — hardly a conservative favorite. Liberals made up 25 percent of 2012 voters — their highest level among the past four elections and 3 percent more than in 2008 — going 86 percent for Mr. Obama. That means Republicans need only a little more than one-third of the remaining Independents to win, while Democrats need a bit less than two-thirds.

In 2016, Democrats also will have to confront “incumbency fatigue.” Eight years is a long time in the harsh glare of today’s presidential spotlight — just ask Mr. McCain, who attempted to follow Mr. Bush. That fatigue runs deeper than just an economic downturn, as Mr. Gore can attest. He failed to succeed Bill Clinton in the Oval Office despite a robust economy. There’s a reason America has had only one same-party three-term stretch (1980-1992) since Harry Truman.

The Republican Party, like Mark Twain, would be right to say, “The reports of my death have been greatly exaggerated.” Ebbs and flows are natural occurrences in presidential politics. Before Franklin D. Roosevelt, Republicans dominated for decades. From 1932 to 1954, it was all Democrats. From Dwight D. Eisenhower through George H.W. Bush, Republicans won seven of 10 elections.

It is a serious mistake to look at the future as simply a continuum of the present. Nowhere is this truer than in presidential politics, particularly now.

J.T. Young served in the Treasury Department and the Office of Management and Budget and as a congressional staff member.