It's Republican debate week for the GOP candidates, and they're all preparing themselves for Monday night's first matchup in New Hampshire. Of the 17 candidates, 14 will speak tonight at the Voters Issues Forum at Saint Anselm College. A moderator will randomly draw questions to ask them, according to MSN.

Donald Trump will not be present at the forum, despite leading in the polls. He will not attend in a show of anger at an editorial published by the Union Leader, a newspaper that is one of the sponsors of the forum.

For those who do participate, the forum is a warm-up for Thursday night's primary debate, the first in a long campaign season leading up to the 2016 vote. Only the top 10 candidates, based on national polls, will be allowed to participate in Thursday's Republican debate. The other seven candidates will square off on Thursday in a pre-debate at 5 p.m. Current poll leaders are Donald Trump, former Florida governor Jeb Bush and former Wisconsin Governor Scott Walker, MSN reported.

The rules of a forum are slightly different than the Republican debate, which will take place later this week, according to Boston's WCVB. Candidates receive questions one at a time in a forum. At the debate, candidates will have the chance to directly address each other. The New Hampshire forum begins at 7 p.m. Monday.

"It's a great event because it has all the candidates on stage at the same time...it treats all candidates equally," New Hampshire Representative for the Republican National Committee Steve Duprey said, according to the Portland Press Herald.

Shortly before tonight's forum, the U.S. Senate will face an important vote on a bill to take funding away from Planned Parenthood. Because they will still be in Washington, D.C, three of the four senators will attend the forum via satellite. Marco Rubio (Florida), Ted Cruz (Texas) and Rand Paul (Kentucky) will not be live at the event.