become more likely to be selected for a more winnable seat. In some cases (especially in the United States), these seats may go uncontested by other major parties. Safe seats can become marginal seats (and vice versa) gradually as voter allegiances shift over time. However, this shift can happen more rapidly for a variety of reasons. The retirement or death of a popular sitting member may make a seat more competitive, as the accrued personal vote of a long-serving parliamentarian will sometimes have resisted countervailing demographic trends. An independent or third party candidate with an ideology close to that of the incumbent party may also be able to make a more credible challenge than more established parties, but these factors can combine: a retiring third-party member may turn a safe seat for that party into a marginal seat. For instance, in Berwick-upon-Tweed, with the retirement of the popular incumbent Alan Beith, the seat was no longer safe for the Liberal Democrats. Traditionally safe seats can also be more vulnerable in by-elections, especially for governing parties. Safe seats may also become marginal if the sitting member is involved in scandal: in 1997, Tatton was gained from the Conservatives by an anti-sleaze independent candidate, despite the majority previously being that of a very safe seat for the Conservatives. The incumbent, Neil Hamilton, had been mired in controversy, and was defeated by the veteran BBC journalist Martin Bell. However, Bell was aided by the decision of the main opposition parties (Labour and the Liberal Democrats) not to field candidates. Without such pacts, a split vote is more likely under a first past the post electoral system, as in the UK. Opposition supporters in safe seats have restricted means to affect election outcomes, and thus the incumbent parties can, in theory, decide to ignore those supporters' concerns, as they have no direct effect on the election result. Even those voters who are moderate supporters of the incumbent party may be disenfranchised by having a representative whose views may be more extreme than their own. Political objectors in such areas may experience marginalisation from wider democratic processes and political apathy. This is often regarded as undemocratic, and is a major argument in favour of various multi-member proportional representation election methods. Safe seats may receive far less political funding than marginal seats, as the parties will attempt to "buy" marginal seats with funding (a process known