Sen. Ted Cruz's two big wins on Saturday bolstered his case that he is the strongest candidate to stop Donald Trump's march toward the Republican nomination, as Sen. Marco Rubio's support faded.

Cruz crushed Trump in Kansas, upset the businessman in Maine, and provided Trump with a tougher than expected challenges in Kentucky and Louisiana.

The results come as an anti-Trump movement began to galvanize conservative activists as well as party elites. Trump came under fire in a Thursday debate, was the subject of blistering attack speech from 2012 Republican nominee Mitt Romney, has been at the receiving end of millions in new negative ad spending, and has received increased scrutiny for his business record and shifting positions on immigration.

Whether any of these factors impacted these results, or whether the results point to the early stages of a Trump fall will keep political experts guessing. The results could merely represent more evidence of his underperformance in caucus states given his lack of traditional organization.

But what's undeniable is that Rubio came in a distant third in Kansas and fourth place in Maine. In Kentucky, he was well behind Cruz and Trump and also battling Kasich for third, prompting Trump to call on Rubio to drop out.

Though the Kansas victory might have been written off on its own given that the state has a large evangelical presence and was won by Rick Santorum four years ago, Cruz's impressive win in Maine pointed toward a broader level of support. Cruz had 46 percent of the vote, to 33 percent for Trump, 12 percent for Kasich, and eight percent for Rubio.

Cruz, a Texas conservative, was seen an ideologically and geographically poor fit for the historically moderate Maine Republican Party. Trump had dominated Cruz in neighboring New Hampshire and Massachusetts. Trump has now lost caucuses — where organization is crucial — in Iowa, Alaska, Minnesota, Maine and Kansas.

The Maine loss also came despite the fact that Trump recently gained the support of Maine Gov. Paul LePage.

The more wins by non-Trump candidates, the greater the likelihood of a contested convention in which no candidates would come out of the primaries with a majority of delegates. Cruz has recently dismissed the prospect of a contested convention as potentially toxic to his party's fortunes, however, and is arguing he can win outright if those who want to stop Trump rally around him.

But it will be more difficult for any candidate to achieve the 1,237 delegates required to capture the nomination if the field remains crowded. Rubio and Kasich both have justified staying in the race because their large winner-take-all home states of Florida and Ohio vote on March 15.

On Saturday, Cruz's campaign announced the opening of 10 offices in Florida, vowing to take the state seriously.

"God bless Kansas and God bless Maine!" Cruz said in rallying supporters in Idaho, a state that votes on Tuesday. "The scream you hear, the howl that comes from Washington, D.C., is utter terror at what we the people are doing together."

Rubio dismissed poor showings from Saturday night's results, arguing that other candidates had built in advantages going in and that he will do better in bigger states that are winner-take-all delegate wise.

Reacting to the results, Rubio tried to argue that he was still gaining delegates and insisted that the remaining states are more favorable to him.

"The states that voted tonight are, quite frankly, some of the states that my opponents do better in, and I realized that going in," Rubio said. "We're soon going to be in a winner-take-all process, and larger states, like Florida, and in other places like that, and that's where we feel very confident as we move forward."

Ryan Lovelace, Al Weaver and Curt Mills contributed to this report.

Editor's note: An earlier version of this story declared Trump the comfortable winner in Lousiana, based on AP projections. But the race tightened since Trump was declared the winner.