Ted Cruz and Marco Rubio Clash Harshly, Filling Void on G.O.P. Debate Stage

The Republican presidential candidates competed vigorously to fill the vacuum created by Donald J. Trump’s boycott of Thursday night’s debate, with Senator Ted Cruz of Texas and Senator Marco Rubio of Florida trading ferocious attacks on immigration and taking fire from rivals seeking advantage in the Iowa caucuses on Monday.

Mr. Cruz and Mr. Rubio, who are behind Mr. Trump in the Iowa polls and hoping for surprise finishes here, were repeatedly confronted with pointed questions about their views and Senate votes on providing citizenship or legal status to immigrants who are in the country illegally. But it was Mr. Cruz who was hit hardest on the issue, as Mr. Rubio teamed up with Senator Rand Paul of Kentucky to portray him as an opportunist.