WASHINGTON — The political veteran with the right resume, but perhaps the wrong last name. The rookie senators and their focus on foreign policy and individual rights. Governors with experience — and baggage. The never-been-elected outsiders, and of course, the billionaire showman.

For the Republican Party, the narrowing of that vast field of presidential hopefuls begins in earnest Thursday with the first debate of the 2016 campaign. At stake for Republicans: not only picking the candidate to represent them in the general election, but also selecting the direction the party will take as it seeks to regain the White House.

“You’re starting off with a lot of candidates who have an initial group of support that reflect a particular element of the party, but nobody is close at this point to putting together a majority coalition,” said David Winston, a Republican pollster.

As in the 2012 Republican primaries, the GOP faces a tug of war between those eager for a candidate with broad general election appeal and those who think the key to winning is nominating a fiery conservative.

But this time, the field of 17 candidates is both larger and more seasoned, making the choice Republicans will ultimately make less certain or inevitable than in past elections.