DES MOINES - Eighteen months before Iowans gather for precinct caucuses, potential Republican presidential candidates have made 24 visits to the state that is home to the first-in-the nation presidential preference contest.

Two of them are in Iowa this weekend.

Minnesota Gov. Tim Pawlenty is making a series of fundraising appearances in Davenport, Dubuque, Waverly and Cedar Rapids on behalf of legislative candidates.

Former New Mexico Gov. Gary Johnson has been bicycling across Iowa on RAGBRAI over the past week and plans to spend part of today at the Dubuque County Fair in the GOP booth.

Although it's his first visit, Johnson has spent more days in Iowa than any of the other 2012 potential candidates, based on candidate tracking by Democracy in Action.

After this weekend, Pawlenty will be tied with 2008 GOP caucus winner Mike Huckabee, the former Arkansas governor and current Fox TV talk show host, and former U.S. Sen. Rick Santorum of Pennsylvania with four visits.

And he'll be back.

Pawlenty is scheduled to be at the Iowa State Fair on Aug. 11 and 12 to campaign for candidates for legislative and congressional candidates.

He's also scheduled to speak at the Hamilton County GOP dinner Oct. 20.

Santorum has visited four times and is scheduled to be back Aug. 16-18 on behalf of state and federal candidates.

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Former House Speaker Newt Gingrich will return for a third visit Aug. 13 to raise women for female Republican candidates.

Huckabee hasn't announced any plans to visit Iowa in the near future.

In the 2008 election cycle, Republican presidential hopefuls made 283 visits for 551 days. Democrats came 264 times and stayed 644 days.

Since the 2008 election, President Barack Obama has been back to Iowa three times and Vice President Joe Biden has been here twice.