Senator Rand Paul is expected to announce his candidacy for the Republican nomination for president on Tuesday, April 7. Paul will be the second declared candidate after fellow Senator Ted Cruz announced two weeks ago.

Paul is seeking nothing less than to transform the Republican party. He wants the GOP to be more libertarian, more inclusive, and less wedded to big business and the establishment.

At the same time, Paul is looking to straddle some issues so as not to offend the Republican base of conservatives. The Washington Post thinks that this muddies his message:

When the presidential buzz began building around Sen. Rand Paul (R-Ky.) a couple of years ago, the expectation was that his libertarian ideas could make him the most unusual and intriguing voice among the major contenders in the 2016 field.

But now, as he prepares to make his formal announcement Tuesday, Paul is a candidate who has turned fuzzy, having trimmed his positions and rhetoric so much that it’s unclear what kind of Republican he will present himself as when he takes the stage.

“He’s going to get his moment in the sun,” said David Adams, who served as campaign chairman for Paul’s insurgent 2010 Senate campaign. “What he does with it from there will have bearing on the Republican Party.”

There are at least two areas where Paul has moved more in line with the conservative Republican base, somewhat to the consternation of the purists in the libertarian movement: adopting a more muscular posture on defense and foreign policy, and courting the religious right.

Where he once pledged to sharply cut the Pentagon’s budget, for instance, Paul late last month proposed a $190 billion increase over the next two years — albeit one that would be paid for by cutting foreign aid and other government programs. His tour following the announcement of his candidacy will include an event at Patriots Point in South Carolina’s Charleston Harbor, with the World War II-era aircraft carrier USS Yorktown as a backdrop.

Paul isn't the first candidate to bow to the reality of the political situation he faces. And as far as I can tell, Senator Paul has not shaded his non-interventionist position hardly at all. It is that, more than his stance on defense spending, that has GOP interventionists accusing him of being an "isolationist."

Rand Paul is also adjusting to changes in the overall political climate, particularly on foreign policy.

Coming out of the GOP’s 2012 electoral defeat, it appeared that many Republicans had grown weary of war and were anxious to shake the George W. Bush brand of interventionist foreign policy. But that was before the rise of the Islamic State organization, with the horrific videos of hostage beheadings, and the descent of much of the Middle East into ­chaos.

Now, the more hawkish forces in the party are again taking the lead. And Paul’s noninterventionist rhetoric is being tempered by declarations such as the one he made at the Conservative Political Action Conference in February that his priority would be “a national defense unparalleled, undefeated and unencumbered by nation-building.” (For the third year in a row, Paul won CPAC’s presidential straw poll.)

Paul’s statements playing down the threat of a nuclear Iran have put him at odds with conservative Republicans in the past. More ­recently, he angered non­interventionists when he joined 46 other Republican senators in signing a controversial letter, authored by Sen. Tom Cotton (R-Ark.), telling Iran’s leaders that any nuclear deal would not be binding past the end of the Obama presidency if it were not agreed to by Congress.

His former campaign manager suggests it's a question of math; how many GOP voters does he win over versus how many libertarians does he lose by shading his views. In the end, it's the perception of Paul as a leader that will matter. His father angered national security Republicans with his positions on defense and foreign policy. If Senator Paul can avoid the pitfalls and traps of taking a doctrinaire approach to those issues, he could separate himself from the GOP field while articulating a new way of looking at the world and the US role in it.

Rand Paul will certainly be one of the more interesting candidates in the race. Whether he is successful or not will depend on how ready Republicans are to follow him in transforming the party.