Kasich’s large lead over Clinton is mostly due to the fact that he pulls in more Democrats and Independents than either Ryan or Romney—who pull in similar numbers of partisans. Though 9 percent of Democrats would go for either Ryan or Romney, Kasich pulls over 15 percent of Democrats. And while Independents are more tepid in their support of Romney or Ryan (roughly 52 percent), nearly six-in-10 Independents would swing toward the more moderate Republican candidate in a general election scenario.
Though a move to nominate a Republican alternative to Trump does not seem to have enough support to actually happen, our recent polling data suggest other Republican alternatives do perform better than Trump against Clinton. This is somewhat unsurprising as hypothetical candidates usually do better than the actual candidates in polling match-ups and it is still very early in the general election contest. Nonetheless, the results provide an interesting glimpse into the strengths and weaknesses of Clinton and Trump across different electoral groups.