Any effort to remove President Trump from office through the impeachment process is going to come up against a brick wall in the Senate, where 20 Republicans would have to defect to oust him.
Though the most recent Gallup poll finds Trump’s approval rating down at just 39% among the adult population, among Republicans his approval rating is 87%. At the comparable point in his presidency, Obama’s performance won the approval of 77% of Democrats. Obama, in contrast, was less unpopular among independents and the opposition party than Trump.
In modern politics, given that turning out the base is crucial to winning and most politicians have more to fear from a primary challenge than the general election, few would be likely to break with a leader as popular among core members of the party as Trump is among Republicans.
If the Ukraine story gets worse for Trump and support for impeachment grows among independents, it will start to squeeze Republicans up for reelection in swing states and districts. On the one hand, they will not be able to abandon Trump and earn the wrath of their party’s base, but on the other hand, if they defend any behavior of his, they’ll run the risk in a general election. This could complicate Republicans’ ability to retain the Senate by making it harder to hang on to seats in Maine, Colorado, and Arizona.