03/03/2016 00:12 EST | Updated 03/04/2017 00:12 EST

Republicans see options for stopping Trump - none good ones

WASHINGTON — Republican leaders anxious over Donald Trump's dominance say they still have options for preventing the billionaire from winning the Republican nomination — just not many good ones.

Party elites are poring over complicated delegate math, outlining hazy scenarios for a contested convention and even considering the long-shot prospect of a third party option. Mitt Romney, the Republican nominee four years ago, planned a sweeping takedown of Trump in a speech Thursday, but it was unclear what impact his words would have with voters deeply frustrated by their party's leaders.

Trump, meanwhile, was setting his sights on the general election. His campaign reached out to House Speaker Paul Ryan's office to arrange a conversation between the two men, and urged Republican leaders to view his candidacy as a chance to expand the party.

"Why can't the leaders of the Republican Party see that I am bringing in new voters by the millions — we are creating a larger, stronger party!" Trump said on Twitter.

Indeed, there was a surge in turnout in Super Tuesday's Republican primaries. While that could typically be a welcome sign for a party that has struggled to attract new voters in recent presidential elections, party leaders were privately grappling with the reality that some of those voters were in fact registering their opposition to the Republican establishment.

Trump padded his lead with victories in seven Super Tuesday contests, with Texas Sen. Ted Cruz claiming three states and Florida Sen. Marco Rubio picking up his first victory of the 2016 race.

Despite Trump's strong night, he was not yet on track to claim the nomination before the party's national gathering in July, according to an Associated Press delegate count. He has won 46 per cent of the delegates awarded so far, and he would have to increase that to 51 per cent in the remaining primaries.

Republican strategists cast March 15 as the last opportunity to stop Trump through the normal path of winning states and collecting delegates. A win for Rubio in his home state of Florida would raise questions about Trump's strength, as could a win for Ohio Gov. John Kasich on his home turf.

The candidates have a high-profile opportunity to make their case to voters in Thursday night's prime-time debate. Retired neurosurgeon Ben Carson all but ended his bid Wednesday, saying he would skip the debate and declaring he did "not see a political path forward."

The Republican mayhem contrasted sharply with a clearer picture on the Democratic side. Hillary Clinton was nearly halfway to claiming enough delegates to win the nomination, when you include her superdelegates — the party insiders free to pick either candidate. If she keeps her superdelegates, Clinton has to win only 40 per cent of the remaining delegates to be the presumptive nominee.

Rival Sen. Bernie Sanders' road is much tougher. He would have to win 60 per cent of the remaining delegates — including superdelegates — to claim the nomination.

Former Massachusetts governor Romney announced plans to speak on the "state of the 2016 presidential race" Thursday in Utah. Romney has moved aggressively to take on Trump in recent days, saying the billionaire's unreleased tax returns might contain "bombshells." But he was not expected to endorse a candidate or announce a late entry into the race himself.

The Associated Press has asked Republican governors and senators if they would support Trump if he becomes the party's nominee. Of the 59 respondents, slightly fewer than half could not commit to backing him in November. A handful of officials, including Massachusetts Gov. Charlie Baker and Nebraska Sen. Ben Sasse, have said they would not support Trump in November, though it was unclear what alternatives they would have.

One long-shot idea rumbling through power corridors in Washington was the prospect of a late third-party candidate to represent more mainstream conservatives. Former Texas Gov. Rick Perry has been approached by "a mixture of people" about being part of a third-party bid, according to Jeff Miller, who managed Perry's failed Republican presidential campaign. But Miller said Perry found the idea "ludicrous."

A more likely, though still extraordinarily unusual, scenario being discussed is a contested convention. Perhaps unsurprisingly, that idea has the most support among those working for opponents' campaigns. Others in the party express concern about the image of the Republican establishment using arcane rules to thwart the will of voters.


Associated Press writers Andrew Taylor, Julie Bykowicz, Steve Peoples, Stephen Ohlemacher and Donna Cassata contributed to this report.

Julie Pace And Kathleen Hennessey, The Associated Press