Romney campaigns in Illinois
Romney campaigns in Illinois Reuters

CBS News is projecting that Mitt Romney will take Tuesday’s Republican presidential primary in Illinois. The estimate is based on early exit poll results and vote totals.

CBS reported that with 18 percent of precincts reporting, Romney had 88,870 votes to Santorum's 44,377. Ron Paul was in third with 14,872 and Newt Gingrich in fourth with 10,934.

Exit polls conducted by the network found that 43 percent of Illinois Republican voters said Romney is not conservative enough, while an equal percentage said his positions were about right. Forty-six percent said Santorum's positions were about right, while 32 percent said he was too conservative and 15 percent said he was not conservative enough.

In the exit polls, noted the report, Romney led his rivals on the question of which candidate best understands the problems of average Americans, with 35 percent support to Santorum's 29 percent and Gingrich's 19 percent.

CBS News estimated that Romney had 493 delegates entering Tuesday, more than his three rivals combined. Santorum had 218 delegates in CBS News estimates, while Gingrich had 120 delegates and Paul had 42 delegates.

Romney won Sunday's primary in Puerto Rico with 83 percent of the vote. Santorum, Gingrich and Paul were far behind, with Santorum receiving eight percent, Gingrich achieving two percent and Paul receiving one percent of the vote.

In a crucial vote last week, Santorum won the Alabama and Mississippi primaries, beating Gingrich who had been under the most pressure to take both states, after winning contests in South Carolina and Georgia.

Previously, Santorum won the Kansas caucuses, receiving 51 percent of the votes. Romney came in second with 21 percent, Gingrich followed at 14 percent and Paul received 13 percent.