Republicans disappointed with their party's current slate of presidential candidates are stepping up the pressure on Texas Gov. Rick Perry to enter the race. And it's looking increasingly likely that Perry will declare his candidacy soon. "I'm getting more and more comfortable every day that this is what I've been called to do," Perry told the Des Moines Register recently. "This is what America needs." How would a Perry run reshape the Republican primaries? Here, four theories:

1. Perry would make the early contests closer
The Texas governor has generated buzz aplenty, says John Whitesides at Reuters, largely because he'll challenge frontrunners Mitt Romney and Michele Bachmann head on. "If he gets in, he plans to run in each of the states with early nominating contests, directly challenging Bachmann in her top priority of Iowa and Romney in New Hampshire." Perry appeals to social conservatives who hate Romney, and has pro-business credentials Bachmann can only dream of, so he should be able to up the excitement factor in the early primaries.

2. Perry would overshadow Pawlenty and Huntsman
With Perry in the race, says Alex Roarty at National Journal, former governors Tim Pawlenty (of Minnesota) and Jon Huntsman (of Utah) would slide further toward oblivion. Both Pawlenty and Huntsman were "at one time considered among the most likely to win the party's nomination," but in a recent NBC/Wall Street Journal survey, they won the support of just 2 percent of Republicans. Without even declaring his candidacy, Perry earned twice as much support, trailing only Romney and Bachmann.

3. He'd unite the establishment and Tea Party
"Perry is clearly the flavor of the month among Republican insiders," say Chris Cillizza and Aaron Blake at The Washington Post. But he has broader appeal than other contenders. Perry is a critic of federal power, has a record of creating jobs in Texas, and boasts party ties that would almost certainly give him the second biggest warchest behind Romney. Add it all up and Perry's "the candidate perhaps best positioned to bridge the gap between the establishment wing and the Tea Party wing of the Republican Party."

4. Perry would give disgruntled Republicans someone to root for
"There's a hole in the Republican primary field you could drive a truck through right now," says the Texas Tribune's Evan Smith, as quoted by He'd be someone evangelicals could get behind, instead of settling for Bachmann despite her broader electability problems. He'd give Southerners a candidate. He'd also be a powerhouse the Tea Party could get behind to build on the momentum they created last year. Big chunks of the GOP base are still looking for a candidate, and Perry "checks a lot of those boxes."