-- An organized effort by some Republicans and conservatives to stop Donald Trump from securing the party's nomination appears to be taking shape as different groups and former candidates are putting their weight behind other efforts.
Who Is Involved
A number of Trump's former rivals have joined the cause against the real estate mogul.
Rubio subsequently dropped out, and today he told his former supporters in Minnesota that Cruz was the "only conservative left in the race."
Sen. Lindsey Graham, who dropped out in December, is providing a similar show of support to Cruz. Cruz's team confirmed today that Graham will be hosting a fundraiser for the Texas senator on Monday, though he stopped short of giving a full endorsement.
"I mean I don’t know that I need to formally endorse," she said. "I don’t know that that part matters.”
And there appears to be a grassroots movement taking shape among conservatives.
Blogger Erick Erickson said he participated in a meeting of "grassroots conservative activists from around the country" to discuss ways to beat Trump, who they do not view as a "real conservative candidate."
He didn't share any names of others who attended the meeting, describing the group only as "including supporters of many of the other campaigns."
Rep. Trent Franks, R-Ariz., confirmed the meeting in a statement, but did not detail the discussion.
How Are They Hitting Trump
There is more to the anti-Trump effort than just closed-door meetings and endorsements.
The number of groups not affiliated with a specific candidate that have produced anti-Trump ads appears to be growing.
Today the Club for Growth released 30-second television spot in Utah, which has its primary next week, criticizing Trump's previous support for government-run health care.
Trump's comments about women have been the basis of an ad released earlier this week by Our Principles PAC, which is run by former Mitt Romney deputy campaign manager Katie Packer.
By The Numbers
More than $63 million and counting has been spent on anti-Trump ads nationwide, according to an ABC News analysis of data from CMAG/Kantar Media.
Almost half of that money -- $32 million – came from super PACs supporting other Republican presidential candidates. Groups that are purely anti-Trump spent $17.5 million on ads attacking the real estate mogul.
The frequency of the anti-Trump spending has also increased dramatically, with nearly nine times the amount of money that was spent in the first half of February being spent this week alone. That breaks down to $2.53 million being spent each day this week, according to the ABC News analysis of data from CMAG/Kantar Media.
What Solutions Are Being Discussed
The proposal put forward by the grassroots meeting, Erickson wrote on his news site, The Resurgent, is calling for a "unity ticket" to bring the Republican party together.
"If that unity ticket is unable to get 1,237 delegates prior to the convention, we recognize that it took Abraham Lincoln three ballots at the Republican convention in 1860 to become the party’s nominee and if it is good enough for Lincoln, that process should be good enough for all the candidates without threats of riots," he said.
Though it wasn't directly mentioned in today's post, Erickson has previously called for a third party candidate to enter the race. The entrance of such a candidate could be viewed as a spoiler for Trump, but Erickson has dismissed those concerns, saying that Trump's potential down-ticket damage is too much to risk.
Conservative radio host Glenn Beck has also spoken out against Trump, and has posted articles on his site about the prospect of a third party candidate.
Trump, for his part, has railed against the GOP establishment.