Marco Rubio is taking his campaign to the crucial early-caucus locales of Iowa this week, and the Florida senator plans to crisscross the Hawkeye State on a private plane instead of a bus after wintry weather slowed down the tour's kickoff.

Republican operatives questioned whether the Cuban-American senator may be too focused on nationally focused effort that emphasizes strong debate performances and television advertising but may neglect the kind of grassroots campaigning that is critical in states such as Iowa and New Hampshire, the Associated Press reported.

But Iowa GOP strategist Doug Gross, who has not endorsed a candidate, told the newswire that he understands Rubio is trying an alternate approach.

"The caucuses are about organize, organize, organize and get hot at the end," Gross noted. But Rubio and his people have "intentionally tried to run a different campaign," the operative added.

Last week, the Rubio camp announced the senator would "be spending three days, December 28 (to) 30, traveling around Iowa on his campaign bus," ABC News reported. But the senator eventually had to cancel the first day of the planned tour on Dec. 28 because a powerful winter storm had hit his destination.

When he finally arrives on Dec. 29, Rubio will be joined by South Carolina Rep. Trey Gowdy, who is set to accompany the senator on all of his stops after earlier endorsing the Floridian, the campaign noted.

As the head of the GOP-led committee that is investigating the Sept. 11, 2012, terrorist attacks on the U.S. Consulate in Benghazi, Libya, Gowdy is often seen controversial figure in Washington. But Rubio tweeted on Dec. 29 that he was happy to have the congressman on board.

"We're proud to have (Rep. Trey Gowdy) on our team," Rubio noted. "He's a phenomenal conservative member of Congress," added the senator, who has been trying to emphasize his own conservative credentials.

In Iowa, Rubio still has some catching up to do as a Dec. 14 Quinnipiac University Poll of likely GOP caucus-goers showed him at 14 percent support -- well behind front-runner Donald Trump and Texas Sen. Ted Cruz.