Republicans leaders declined to strike a deal and hold a vote on the issue, leading Democrats to then filibuster legislation that would effectively prevent the resettlement of Syrian and Iraqi refugees in the United States.

The flare-up could be the first of many in the Senate this year with Democrats promising to continue to try to tie their GOP colleagues to controversial proposals from Trump, the front-runner in the Republican presidential campaign.

The Wednesday vote to begin considering the refugee bill failed on a 55 to 43 tally, with 60 votes needed to advance the legislation. The bill, which the House passed last month, would suspend the admission of Syrian and Iraqi refugees until the Obama administration can certify that no one coming to the United States poses a security threat.

Congressional Republicans have been wary of Trump and his populist rhetoric, but they are finding it harder to ignore him as polls continue to show he is leading the Republican presidential race just a few weeks before voters are set to caucus in Iowa on Feb. 1, the first contest in the 2016 presidential race.