Ron Paul is the Butler Bulldogs of Republican presidential politics.

Butler, you may recall, is the second-tier — a.k.a. “mid-major” — college basketball program that made the NCAA Final Four two straight years in 2010 and 2011, only to lose in the National Championship game to storied programs from Duke and Connecticut.

Republican presidential candidate Rep. Ron Paul (R-Texas) talks to supporters during a rally Saturday, March 10, in Springfield, Mo. (AP Photo/Charlie Riedel)

But then, reality set in. While Paul has had a great campaign season for a “mid-major” candidate, things have certainly tailed off in recent weeks, and it’s clear that Paul is still missing something that the Dukes and the UConns and the Mitt Romneys of this world have: staying power.

Paul, whose campaign doubled its vote total from 2008 in 12 of the first 19 contests he participated in this year, has failed to do that in the last five contests for which there is a comparable result between 2008 and 2012.

After cracking double digits in all but two contests through February, he’s finished below 10 percent in seven states this month and four of the last five states.

Mississippi’s primary earlier this month was the first contest this year in which he failed to improve upon his 2008 showing. Just like four years ago, he took 4 percent — his worst showing of the 2012 campaign so far.

Things don’t look like they will rebound any time soon. Paul has spent considerably less time on the campaign trail since Super Tuesday, his super PAC support appears to be drying up, and his campaign’s focus on performing well in caucuses doesn’t work so well in the second half of the campaign, when all but two contests are primaries.

The practical effect of Paul’s campaign has been pretty minimal as well. While his campaign has talked a lot about being a player at the convention, right now he is projected to have won 50 delegates, which is higher than the approximately 30-35 delegates he won in 2008 but still far from being a contender when you consider that there are more than 2,000 delegates available.

That said, the campaign’s inability to continue its momentum shouldn’t take away from the improvement it showed. Like the Butler Bulldogs, it beat expectations and turned itself into a player in the presidential process — someone that people had to talk about.

(Which really was probably the goal from day one, no matter what the campaign says.)

Like Butler, Paul wasn’t supposed to win the nomination and basically nobody thought he would, and that lack of an expectation is what makes his campaign a success.

While Paul has yet to win a contest, he has taken second place in seven states, including the New Hampshire primary. At this point in 2008, he had only finished that high in Nevada.

He has also doubled his vote total from 2008 in half the contests this year.

Paul also took more than one-third of the vote in the Maine caucuses and 40 percent of the vote in a one-on-one matchup with Romney in the Virginia primary — proof that his appeal has broadened and that plenty of Republicans will vote for him under the right set of circumstances.

That perception change has been perhaps the biggest shift. It’s easy to ignore a guy who is mostly stuck in the single digits. But for a time in the Republican presidential campaign, Paul was threatening to win Iowa and was regularly cracking 20 percent of the vote.

All of a sudden, you have to talk about a guy like that.

“We have proved, and continue to prove, that Dr. Paul’s message of limited government and respect for individual liberties can win in states where we have the time and funding to execute a comprehensive campaign strategy,” said campaign manager Jesse Benton. “We crushed better-funded, establishment-favored candidates in Iowa and beat the field in New Hampshire, presidential swing states with very different electorates.”

At the same time, Benton acknowledged that sustaining a viable presidential campaign for the long haul is tough when you’re one of 435 members of Congress and have a libertarian-leaning political philosophy. Because whatever success you have, the institutional obstacles remain.

“Overcoming the earned media deficit and scorn of the Beltway chattering class is difficult, but Ron did it in the two most high profile states in American politics with smart campaigning and the right message,” Benton said.

The bad news for Paul is that, like Butler, sustaining the momentum has proven difficult.

Despite their consecutive national championship game appearances, Butler failed to make the field of 68 teams in the 2012 NCAA Tournament this year, finishing the season a very pedestrian 20-14.

But at least for a few years, when people think of the underdog making a statement, they will think of Butler, who for a couple seasons danced with the big boys.

That’s what Ron Paul did this year.

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