If Reagan stayed a Democrat

[True Federalist (진정한 연방 주의자)]

The Democratic Party at one time was the more libertarian of the two major parties.  But then the meaning of "liberal" changed in American politics to not be the same as libertarian .  The Democratic Party remained liberal, but Reagan remained libertarian. At the same time, because big business sought more to protect itself from government than to make use of government as it had pre-Roosevelt, the Republican Party became more accommodating of libertarianism. So, without changing Reagan, for him to remain a Democrat requires both that the Democratic Party not abandon libertarianism and the Republican Party not try to bring libertarians into its tent.  I once began, but did not finish an alt hist timeline in which the Democrats changed as per OTL but the Republicans did not and Reagan became one of the founding stars of the Libertarian Party.

[True Federalist (진정한 연방 주의자)]

The Democratic Party at one time was the more libertarian of the two major parties.  But then the meaning of "liberal" changed in American politics to not be the same as libertarian .  The Democratic Party remained liberal, but Reagan remained libertarian. At the same time, because big business sought more to protect itself from government than to make use of government as it had pre-Roosevelt, the Republican Party became more accommodating of libertarianism. So, without changing Reagan, for him to remain a Democrat requires both that the Democratic Party not abandon libertarianism and the Republican Party not try to bring libertarians into its tent.  I once began, but did not finish an alt hist timeline in which the Democrats changed as per OTL but the Republicans did not and Reagan became one of the founding stars of the Libertarian Party.

Reagan was still a Democrat in 1948.

And in 1948 the divergence between liberal and libertarian wasn't nearly what it would become. Business hadn't yet come to generally see government as more of a hindrance than a help. Also Reagan wasn't that political in the 1940s. It was the 1950s that saw Reagan switch from acting to politics.

[True Federalist (진정한 연방 주의자)]

The problem with that idea is why would Reagan giving a powerful speech in favor of LBJ bring him much attention in 1964? LBJ was so completely favored both in the primaries and the general election that no speech in favor of him, no matter how good, would bring attention to the orator. You'd either need to have Reagan do something meaningful in 1960 or 1968 if you want to have him remain a Democrat and rise to political prominence. Perhaps something like his "A Time for Choosing" speech but done in support of JFK in the 1960 Democratic primaries? Then perhaps Reagan defeats Kuchel in the 1962 Senate race? (Uness you think he'd try an intraparty contest against Brown in the gubernatorial contest?) Alternatively, Brown appoints Reagan instead of Sallinger to the Senate in 1964 after Engle dies, setting up an contest between two former SAG presidents in the full term 1964 election when he faces George Murphy. Assuming Reagan beats Murphy, a likely butterfly is that The Candidate is never made as that movie was reportedly inspired by Tummey's defeat of Murphy in 1970.

A senatorial career for Reagan sets up the possibility of a Carter/Reagan (or Reagan/Carter) ticket in 1976.

Yeah, the more I muse on this, if you want an interesting Democratic Reagan timeline, having him come to political prominence four years earlier than in OTL with a pro-Kennedy speech in 1960 is probably the way to go.