Mitt Romney won the Oregon primary on Tuesday, taking the bulk of the state's 28 delegates and pushing him closer to officially winning the GOP nomination.

The Associated Press called the race for Romney shortly after polls closed at 11 p.m. ET.

Romney is the presumptive GOP nominee but needs 1,144 delegates to clinch the nomination -- a number he should hit by the end of the month or in early June.

This week, Romney’s last challenger in the GOP primary, Texas Rep. Ron Paul, said he would stop campaigning in states that have yet to hold their primaries, and instead focus on cultivating his delegate count in states that have already held their contests.

Romney’s prospects for winning the Beaver State in the fall election are bleak – Oregon hasn’t voted for the Republican presidential nominee since 1984. However, a surprising SurveyUSA poll released last week showed Romney within 4 percent of President Obama.

Obama defeated Sen. John McCain in Oregon in the 2008 election by 16 percent.