Pundits and his opponents in both the Democratic and Republican ranks continue to pummel Mitt Romney as one of the weakest GOP front-runners in recent memory.

But Romney has done something that no other Republican presidential candidate who wasn’t sitting in the White House has done. He won the Iowa caucus, if even by the skin of his teeth, over Rick Santorum, and, on Tuesday, he won the New Hampshire primary.

Despite almost knocking off Gerald Ford in Iowa in 1976, Ronald Reagan lost out to George H.W. Bush in the Hawkeye State in 1980. Reagan went on to crush Bush in New Hampshire and went on to win the nomination.

When Bush ran for president in 1988, the scenario was reversed. Instead of winning Iowa, Bush came in third -- behind Bob Dole and evangelical leader Pat Robertson. Bush rebounded to win New Hampshire and, after routing Dole in South Carolina and on Super Tuesday, took control of the race.

Unlike Bush, Dole kept his base in Iowa when he ran for the Republican nomination in 1996. But Dole stumbled once again in New Hampshire, losing out to conservative commentator Pat Buchanan. Dole went on to win South Carolina, paving the way to grasping the Republican nomination.

George W. Bush followed in his father’s footsteps in 2000. Bush won in Iowa but was upset by John McCain in New Hampshire. Bush -- like his father and Dole -- scored a big win in South Carolina and went on to win the nomination.

McCain, once again, lost Iowa and won New Hampshire in 2008. Mike Huckabee won Iowa and Romney fought McCain in the Granite State. McCain went on to win South Carolina and was off to win the nomination.

The Romney team flirted with focusing heavily on Iowa as a stream of conservative candidates -- Michele Bachmann, Rick Perry, Herman Cain, Newt Gingrich -- rose and fell in the Hawkeye State. In the final weeks of December, Romney rolled the dice and focused on Iowa.

Romney beat Santorum by only eight votes -- a testament to the former senator’s impressive grassroots effort in campaigning in all 99 counties in Iowa. But Romney scored a solid win in New Hampshire and, if polls are to be believed, is set to win the next two contests in South Carolina and Florida.

Romney certainly has his flaws and is not arousing much passion from the base. More than a few pundits have compared him to another presidential candidate from Massachusetts who won both Iowa and New Hampshire -- John Kerry, whose record of flip-flops helped lead to his defeat in 2004.

There’s some gist to the Kerry comparison but, even with his support of the state health-care law in Massachusetts, Romney will not be as vulnerable as his fellow Massachusetts politico was. Leading a state as governor allows a politician to avoid some of the legislative traps that can ensnare senators who have their eyes on the White House. It’s one of the reasons why only three sitting senators -- Warren G. Harding, John F. Kennedy and Barack Obama, none of them leading figures in the Senate -- went on to win the presidency.

A Gallup poll released on Tuesday finds that Romney is the most acceptable candidate to moderate and liberal Republicans. Fifty-nine percent of them say Romney is an acceptable candidate. But the same poll finds that Romney is also the most acceptable candidate to conservatives. Once again, 59 percent of conservatives said they think Romney is acceptable. According to the poll, Romney is acceptable to more conservatives than Santorum, Newt Gingrich, Rick Perry and Ron Paul.

Romney’s successes in winning Iowa and New Hampshire, and in making himself acceptable to moderate and liberal Republicans as well as conservatives, are no mean achievements.